Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, please

I hate to keep coming back to the "knowledge well," but you folks have been more than kind with your opinions, and I've taken a lot of notes... I have just read SO MUCH in such a short time that I'm second-guessing myself... And I didn't want to pollute this thread with the misinformation I posted in another thread...

So, OF COURSE it was too good to be true! The "rebuilt" (As in: "rebuilt 1972 350-4V, $150.00" ) consisted of someone slapping new crank and rod bearings on it, and putting in new gaskets. At least the guy decided to put anti-seize on the head bolts, so those came out without a struggle.

Meh... I'm not too broken up about it. I have $310 total invested in 3 engines (two 350-4V's and one 350-2V) to pick and pull from, if you will, to assemble one decent motor. I have two full sets of accessories, two 350-4V intakes and two Rochester Q-jets.

From what I can gather, the 350-2V is a '72 model (WC code), as well as the "rebuilt" 350-4V motor above (WB code). The fully assembled 350-4V motor has had the block decked, as there is no number evident - however, the heads have a "'73" cast into them...so I'm suspecting that it's a '73 motor.

OK - my game plan is to disassemble all three motors, and pick/choose the best components of the lot to take to be serviced. I decided to take the best parts to a local, well-reputed machine shop to clean and inspect the parts, do a valve job, and a basic hone and rering if I can get away with it. (OK, so three places I called all referred me to this one place. The owner's name is "Stump." He's been doing this since the 70's, and when I talked to him about the grooved cam bearings, he mused that it was good that they finally fixed that weakness on the Buick 350. You CANNOT make this stuff up...)

So, any advice as to mixing and matching the parts and pieces to assemble one complete 350-4V? Any incompatibilities between years? I know the '68-'69 heads oil differently, but other than that, any issues with swapping parts around??

Once the machine shop is done, I will assemble from there. I've already ordered a Crower level I Cam, Crower lifters, and TA cam bearings, and oil pump will will get a TA restrictor plate and TA adjustable oil pressure relief valve. Blah Blah Blah. Trying to keep total engine cost under $1000, so I have about $700 to play with.

Questions:

1: Any better year for block numbers between '72 and '73?

2: If I can get away with a hone and rering, which year pistons are better? The pistons in the one I tore apart are recessed (?? - is that the term? basically flat, with a recessed circular center section) - haven't opened the other two motors yet.

3: What about heads? Preferential years? I've read so much conflicting info over the past month that my head is swimming...

Note - this is for a "little bit better than stock" rebuild for a 4x4, so I am not racing this beast. Reliability, low end torque, and efficiency are the three most important rating criteria - and regular 87 octane.

FYI - this is what the machine shop quoted me for prices today -12/31/13 - I think it sounds reasonable - what do you think?

Block: Hot tank, mic, magnaflux and hone the block: $175. If bore required: extra $75, for $250 total.
Crank: Mic and polish: $45, $110 if required to be turned
Heads: Valve Job (hot tank and inspect/magnaflux heads, lap valves, put in new valve guides and reassemble): $80 apiece for $160 total. Installing hardened exhaust valve seats is only an extra $8 per valve, for $64

If I have funds left over, I will probably take him up on this additional service:

Assembling the short block: $175 plus parts; Long block: $250.

Thanks again - I just don't want to set myself up for disaster by mating incompatible parts...

 

Re: Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, pl

Measure from the piston top to the deck surface and use which ever block measures the least, that is the piston is closer to the deck surface.

1970 hi comp pistons have a smaller dish otherwise all are the same up to 1975.

Some will argue about this but all the 350 heads flow the same up to 1975. Some say after 75 they get worse. I've never checked any.

DO NOT have hardened seats installed. Buicks use higher nickel iron that does not need the seats. You will only weaken the heads in an already crack prone area.(between the valves)
1973 and newer had cap screw rods that are stronger than the older nut and bolt rods. For a low RPM engine it really does not matter.

 

Re: Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, pl

Steve - sweet - thanks for those nuggets! I owe you a beer. You saved me $64 (at least!!!)

Sean posted this in another thread...

"You cannot use 73-80 heads on a 68-72 block as there is an extra coolant passage that will not be covered on the early blocks and you will end up with a mix of coolant and oil... So if using the early block use the early heads...The 73 block could use any head from 68-80 without an issue..."

I guess the optimum plan would be to see if the '73 block was decent, and then select the best heads out of all of them.

 

Re: Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, pl

If the one engine is a 73' and you use an older block,don't use the 73 heads unless you use the 73 block. 68-72 heads will work on 68-80 blocks,but 73-80 heads will only work on 73-80 blocks. Because of an extra coolant passage in the 73-80 heads that will leak if they're not plugged when using on the older blocks.

68-69 350s oil through a passage from the deck surface through the heads,you can still use these heads on a later engine,but use the later rocker shafts that oil through the push rods.

The 73-80 engines have the better rods,but with the level of your build that shouldn't matter,chose the better pistons in your case that will meet your compression needs.

To measure the CCs of the pistons without the proper tool,you can go to the drug store and buy the biggest syringe(without the needle) that has CC measurements on it. When you get it home fill it with water and keep track of how many CCs the dish of the piston will hold.(a piece of flat clear plastic with a hole in it on top of the piston would make the measurement more accurate,but optionable) Most factory heads are around 58CCs,you can use the same method to measure the chamber volume,but a thicker than water liquid should be used because water will seep faster past the valves.(like W-D 40 or diesel fuel,or something like that)

1)As for the block,with your mild build and not boring and only honing,chose the one with the best bores.

2)All sbb 350 pistons are dished,some dishes are bigger than other dishes,so chose the ones that fit your compression needs better after you measure them. They are probably all cast ,if you have a set of forged pistons in one of the engines it was probably bored oversized and are aftermarket pistons. For your level of build forged pistons aren't nessesary,so chose accordingly. If you can,try to keep all the rotating assemblies together so you don't have any balance issues.


3)As for the heads,flow is usually your friend and the consensus I've read on here is that the 68-72 are more prone to crack but flow better than the 74-80,the 73 heads are still a mystery and the 73-80 are less prone to cracking.

The machine shop prices seem reasonable,but make sure they understand Buick rod and main clearances if they grind your crank. You don't want more than .002" clearance on the rod and main bearings,tell them you want between .0015"-.002" for both,or you will have crappy oil pressure if they go bigger.(its not a chevy) Have the machine shop measure the deck height for you too so you can figure out you CR .

After they disassemble the heads have them call you so you can pick them up and do a little port work on them. All you'll need is to gasket match and bowl blend the intake side try not to make the intake side to smooth though. On the ex. side you want to try and polish as smooth as you can get it for good ex flow by only taking the flash out and smoothing,no need to open them up,except for a ex gasket matching. But if you do the ex G/M make sure you port the ex manifolds also so they are slightly larger than the ex port so theres no reversion.(you want a smaller hole flowing to a larger hole so the flow isn't interupted by a ledge) Even with the level of your build these mods will work wonders. On the intake manifold ports if you decide to gasket match port those also,make sure they're slightly smaller than the intake ports on the heads so there isn't any reversion there as well.

If you can hold onto the other engine cores after you have one complete engine because when TA starts selling sbb 350 aluminum heads the prices of sbb 350 cores will go up.

Goodluck I hope I was helpful,and Happy New Year to you and everyone that reads this!

Derek

 

Re: Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, pl

If this were true, GM would not have bothered to harden the exhaust seats via induction starting in the early '70's.

The whole "higher nickel iron" is true of every GM division except Chevy; and EVERY ONE of them went to hardened seats in the same timeframe. Most hardened exhaust seats are done by induction hardening the parent metal, and sometimes--less often--by installing hard seat inserts.

Any machinist that can't do a fine job of installing hardened exhaust seat inserts shouldn't be in the business.

 

Re: Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, pl

True they did harden the seat area of the parent metal but did NOT bore a hole and install an insert. I have never had a problem with a stock seat on any 350 or 455. I have found some 350 heads cracked between the seats. So I know that area is weak. Removing parent material from there is not a good thing to do. Putting an insert in does not make in stronger.

 

Re: Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, pl

Actually, I think hardened seats is what AM&P did when they ported and installed the new valves in the heads for the 350 that was on Hot Rod TV.

Looks like we have a debate starting to go on this. What does everyone else think?

---------- Post added at 09:24 AM ---------- Previous post was at 09:18 AM ----------

I also hope this will be sent out to sea with the Aluminum Heads that are about to be built.

 

Re: Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, pl

To maybe put an end to this "debate" before it even starts,the OP engine doesn't need to spend the extra $$ for his level of build with a low compression and low rpm engine.

He is only getting a basic valve job without putting the larger valves in,so most of the induction hardness should remain.

Derek

 

Re: Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, pl

 

Re: Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, pl

Yes, they put in larger 1.94 intakes and left the exhaust 1.505 (or just 1.5). Maybe that matters, maybe not. TA advertises their 'Stage1' 350 heads with 1.92 intakes and 1.55 exhaust WITH hardened exhaust seats.

I've heard it both ways. I think I got into this debate once with someone on these boards a while back. I don't remember how it turned out. lol

I do know that the heads were heat treated around the exhaust seats from factory to compensate for the absence of lead in the gasoline in the later years (around '74?) on all engines, not just Buicks. Buick has a high nickel content in their heads, which they say makes the entire head 'hardened' though some say everyone but cheap Chevy did that as well.

I imagine a person could get away without the installed hardened steel seats as long as not too much material was removed from the head casting.

I haven't heard much about the cracking between the valves as Steve says, though I don't doubt his word. It makes sense that removing native material around an already crack prone head would compromise the structural integrity of the head. This may very well be a case where it's a case-by-case scenario, like with core shift in blocks.

So technically, both sides of the story may be correct.

If it were me, I would play it safe and go ahead and put a set of hardened seats in before anything else was done to the head (after magnafluxing to check for cracks). If the heads looked good and the steel seats were a success, then go ahead and move on to the port/cleanup/polish work.

My 2c

Gary

 

Re: Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, pl

IF the seats were induction hardened, and IF you don't grind through the thin hardened layer while renewing the valve seat, (and how would you know?) then you'd likely be fine.

I want to emphasize that there's pretty much no way to know whether the hardened layer has been breached.

The myth about nickel in the iron meaning that you don't need hardened exhaust seats is PURE BULLSH!T.

GM, who had more engineers than you can shake a stick at, didn't believe it in '72, why does this fable have traction with a bunch of enthusiasts forty years later? THINK! GM clearly knew how much nickel they were putting in the iron, and yet they still spent the time, money, effort, and enthusiasm to harden the exhaust seats in production.








Just to take this one step further, have you considered that if you remove the hardened (and apparently brittle and crack-prone) metal of the existing exhaust valve seat, so that the machinist can then install a seat insert, that process may prevent the head from cracking in the first place? If the head is cracked between the seats, as long as the crack doesn't go deeper than the seat inserts, you could cut the intake and exhaust seats for inserts, and completely remove the existing crack(s) in the process.

 

Re: Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, pl

If GM thought it was so important why didn't they install the inserts? I have NEVER seen any pre 1980 GM head, Buick or otherwise come from the factory with inserts.

If you cut out parent material and install inserts it will be more easily cracked. The insert will not add strenght.

I had my 396 Chevy heads cut for L88 valves in 1985, no inserts and it still runs fine. If Chevy did the induction hardening that would have been removed in the process.

 

Re: Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, pl

The important part isn't that it has or doesn't have inserts. The important part is that the exhaust seats are hardened.

Induction hardening of the parent metal is a viable solution...in production. Problem is, it may not survive the grinding needed to freshen the seats.

If the parent material is brittle, removing it may not add strength, but it may remove a weakness. I haven't seen evidence that heads are more crack-prone after having seat inserts installed...have you? The big complaint I hear about seat inserts is when the wrong insert is selected, or the casting is thin, so that when the machinist cuts into the head he opens up the water jacket. Even that is fixable most times, but it adds to the cost.

Last year of 396 was 1969. Replaced in '70 with the 402, although they may still have been called 396. At any rate, if the heads were older than about '72, they weren't hardened to begin with.

You got lucky. SOME folks get away with non-hardened seats. Low mileage, low rpm, low load all make life easier on the exhaust seats. High mileage, high rpm, high load make the seats more prone to recession. Ya pays your money, and ya takes your chances.

 

Re: Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, pl

I have not seen heads crack more often when inserts are installed but I don't work on heads all day either. Think about it, when is something stronger when material is removed?
I have seen inserts fall out and that takes out the valve, piston, sometimes the rod or worse.
I agree grinding the seats does remove some of the hardened area. Again, the base material is fine. I've never seen a Buick head with burned/eroded iron seat.

My Chevelle heads are 72 smogger heads, don't know it they were ever hardened, but that surely would have been removed going to the larger valves. Car runs low 12's, I shift at 6500 so its not babied but does not get driven as much as it should.

 

Re: Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, pl

Not to add fuel to the debate but I can add clarity to why GM didn't add seats. Working for GM for 30 years it usually boils down to which fix will be the most economical to put in place. It was simply a matter of money. It was cheaper faster, and most importantly it worked to induction harden the area around the exhaust valve instead of adding an additional machining operation and additional parts. They also knew that machining material from a marginal area would require changing the head slightly. This would have add cost, time and material even beyond the machining process. Adding an induction heat treat operation to the area was the best fix based on production runs in the millions.

 

Re: Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, pl

Wow so many issues to address... (not picking on you Schurkey, I'll be speaking rhetorically and using some of your words as a basis)

The induction hardening process is likely to reach down a ways into the metal...likely past where any truing up of the seat would be, unless you had to really grind down in there a ways, I'd say the hardened metal is still present--at least enough to allow a work hardened surface after some miles, anyway.

If you have to grind it all out for bigger valves, then I'd say it's safe to say it's not there anymore.

While true, this logic can also be applied to

where you wouldn't know until after you were finished grinding.

This would certainly be a fix for a crack in this area though, providing it didn't go deep enough, and you put inserts into both intake and exhaust, which is adding up on the final bill.

So why did they put nickel in there? Just to add to the cost? Nickel adds strength and helps to resist wear. Surely it was to at least help with this problem, even if it didn't solve it 100%.

Which leads me to

Engineers tend to over-engineer everything to play things on the safe side. We know more now about things, particularly seeing how everything is now decades into hindsight, than they did then when things were brand-new. Maybe they were just playing things safe, seeing as how millions of production units were at stake, and one mistake could have cost them their jobs and millions of production labor hours.

The idea and implementation of low-lead and eventually no-lead (unleaded) were pretty new in '72, so they had very little actual experience to go by as to how the seats would actually react, so they played it safe.

So technically, heat induction hardened seats were overkill.

Remember these were production engines designed to be everyone's daily drivers back then when this was all there was to drive. These engines were engineered to see every possible driving scenario, from grandma putting round on the roads at 20 MPH to the 18 year old lead food son who took Dad's Buick out on the weekend to burn some rubber and see how high she'd rev, to the late 20's early 30's middle class man with an appetite for adventure and speed, all of whom may or may not have bothered to check to make sure the oil and coolant levels were optimal on a regular basis, etc.etc.

Both my '68 Buick 350's were factory stock, didn't have hardened seats or heat induced hardened seats, lived most their lives on regular leaded gasoline until I owned them, advanced the timing, and put Ammoco Ultimate premium 93 octane UNLEADED in them.

Both engines ran fine for many many miles this way. Not saying it didn't do any harm, but it can be done without any apparent (driver-visible) ramifications.

What did these engines have that prevented the valves from burning? I suppose that nickel in the heads helped some, and maybe the fact that the seats were nice and work-hardened. Or maybe I got 'lucky' (twice in a row)

I'm not sure if you honestly believe this, or if you're just grasping at straws to find an argument? Either way, this is clearly what is the "BULLSH!T" you called the nickel in heads earlier.

A couple of issues this brings up: Thermal transfer won't be any different using steel inserts vs the native material. Though this steel is much stronger and therefore less prone to anything the nickel-iron is, the steel inserts are still separate entities and won't prevent the rest of the head from anything other than recessed seat/burnt valve/ anything valve related.

...and as such, wouldn't do anything but add to the chance of cracks (which is mostly heat related anyway and can be resolved with more modern techniques, as was touched on earlier) or possibly stretches and/or recession of the steel insert itself into the native iron (nickel would greatly help to reduce this tendency, btw) which can cause the steel insert to lose traction within its own seat and 'fall out' as Steve has said, and causing potential catastrophic failure.

Though I wouldn't worry about steel seats in Buick heads, if done properly.

EDIT: To be fair, there is an afterthought of legitimacy to this idea. Heat treated metal may tend to be more brittle and therefore more crack-prone, therefore removing this metal as a pre-emptive measure against cracking (though if it hasn't cracked after 40+ years of use, not sure why it'd start now) to install inserts is logical.

Also: later model heads ('75+ I think) were 'less crack prone' according to research, because of (presumably) thicker material. So maybe the seats were made thicker and less likely to crack with this heat treating process that was prevailent throughout these years... (which is another chalk up for the later model heads as viable alternatives) Which also means that these later model heads would be much safer to use as steel seat candidates once the hardened native iron was removed (for larger valves?).

Last but not least:

Things that affect valve seats.

This includes, camshaft design (hint hint) and/or valve spring pressures, driving habits, mileage, climate, extremities of heat cycles, etc.

Anything that's going to be harder on the valve seats is going to add to their chance of failure, and vice-versa.

Saying anything or everything is absolutely, definitely, without a doubt a certain way when there's just so many variables and parameters that could alter the outcome just isn't true.


Did I miss anything?

Oh yeah...lively debate is healthy as long as an agreed upon outcome can be achieved, even if that agreed upon outcome is to 'agree to disagree'

So everyone play fair, wear your jock straps, and have fun!


Gary

 

Re: Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, pl

To address this comment: "there's pretty much no way to know whether the hardened layer has been breached"

Why can't you do a hardness test in the area you're interested in? Brinnell Hardness test, or Rockwell, etc. Pretty standard hardness tests.

Now, if you meant that there's no way to know with the naked eye, then yes I'd agree. But there are hardness tests that can be done to know exactly what the tested area hardness is. The basic method is you drop a small punch stylus onto the metal from a known height with a known weight, then measure the dimple depth and use the charts to determine the specific hardness.

 

Re: Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, pl

duplicate post. Sorry.

 

Re: Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, pl

I've never done an analysis of the iron alloy used for heads. I'm trusting the internet to not have gotten this wrong. Everything I know about nickle in iron is based on bore wear, which is to say that Chevy bores tend to have a lot of it, relative to the other GM brands. Nickle in the iron of the block does tend to reduce bore wear. Whether nickle in the iron of the head reduces valve recession is somewhat debatable, since the wear mechanism is completely different from bore wear. Maybe nickle in the iron of the head reduces valve guide wear, which Chevy small-blocks also tend to have a lot of, and the GM siblings seem to have less of, based on my limited experience. Chevy big-blocks don't use the iron of the head as valve-guide material, and it may be that some of the other GM divisions also used separate valve guides, too.

My money is on the "work hardened" part.

(Just to be clear, I didn't call nickel in heads "BULLSH!T"; I said that nickel in heads is not a substitute for a hardened exhaust seat, it's the myth that nickel is a substitute for a hardened exhaust seat that is "BULLSH!T".)

Seat inserts don't fall out unless they were installed incorrectly, or unless the valve hits the piston first. (Seats may fall out of an aluminum head if the head is wildly overheated.) Smacking a bent valve into the seat insert might loosen it, but that's not the fault of the insert.

I didn't realize that Buick had problems with head cracks between the seats. I haven't seen it, anyway. However, IF this is common, I'd want to cut out the crack-prone, brittle metal if at all practical; and I'd want to do it BEFORE sinking a heap of time and money into the castings.

I don't worry about seat inserts in ANYTHING, if done properly. (Ok,Chinese aftermarket aluminum head castings might worry me, because the Chinese are known for not bothering to heat-treat the aluminum. ANYTHING can happen when the casting is that poor.)

 

Re: Well, "Rebuilt" was only half the story. The other word was "Needs"... Advice, pl

More thoughts I'd like to add to this conversation:

The use of those stainless steel swirl polished valves may act as a reverse 'hardened seat' in the sense that instead of it being the seat itself, it's now the valve doing the action. (possibly) The only way this wouldn't work is that with a 'burnt valve' the valve itself isn't a contributor to the process--that only the seat is the culprit (see below).


Here's the logic: the reason seats recess is when cam/valve spring parameters are as such where the valve closes too harshly and 'drives down' the seat into the head, creating a looser fitting spring and exacerbating the circumstance.

A 'burnt valve' is where the seat isn't hard enough and gets too hot (which is why it happens primarily on exhaust valves and not intake valves), causing parts of the seat and valve to 'stick' together, then when the valve opens, it pulls off little pieces of the seat and over time will create pits and irregularities in the seat, creating blow-by when the valve is closed.

To remedy this, better metal that can withstand higher temperatures was used (nickel iron) and/or heat tempering the exhaust seat, which was more cost-effective than installing steel seats from the factory.

A possible side-effect of this heat treating process is a more brittle metal, potentially contributing to head cracking (at least between the I/E seats where it's thinnest).

An idea is the use of harder valves (stainless steel, swirl polished) to help remedy this potential problem, unless of course the valve has nothing to do with it, though I'm sure it certainly wouldn't do anything but help the situation.

Possibly the fact that there's nickel in the head already, no matter whether or not the hardened metal was removed (which it WOULD be for these larger valves), coupled with the use of these valves, would eliminate the possibility of a 'burnt valve' scenario, as long as the camshaft/spring pressures were easy on the valve train, and a few miles were accumulated before any harsh driving was attempted, in order to work-harden the seats.

To play it safe, installing steel exhaust seats wouldn't be out of the question (in my book), along with the use of the aforementioned valves.


Gary

---------- Post added at 12:56 PM ---------- Previous post was at 12:39 PM ----------

Fair enough, and you present a valid argument. I still say it's on a case-by-case scenario, though to play it safe, I'd go with steel seats myself. But to say a person absolutely needs them (in a Buick head) isn't true.

Valve guide wear may be the reason for nickel in the heads, though I'm sure the valve seats certainly saw some benefit. It's not just the back and forth scuffing wear it helps with, though valves will spin too, so the seat will see some as well, just not as much.

So as long as the metal scrapes past another metal, nickel works. But if it's being hammered, it doesn't? That doesn't sound legit to me.

I'll go with you on the fact that nickel isn't the magical cure-all and you absolutely will not ever need hardened seats because of it, but it certainly helps (in more ways than one) and as a counter point I'll say that it doesn't mean you WILL need steel seats installed, like you would with a set of heads that didn't have nickel.

I'd say if the seats look good when redoing some heads and all they need is a good cleanup, then I wouldn't worry about it (if it's a Buick head, that is). Odds are pretty good it'll be just fine.

Now if it's recessed and looks pretty rough and/or larger valves are going to be used, I'd say go ahead and put steel inserts in. To work harden a thinner area around water jackets may be asking for a cracked head, regardless of how hot it gets.

Theory and 'on paper' debate/calculations aside, what ultimately matters is real-world experience and how things turned out. I know for a FACT that untouched/untreated '68 heads did just fine off unleaded gas for years and 1,000's of miles (and those were HARD miles, let me tell you).

Others say they never put hardened seats in Buick heads and everything turns out just fine. So let's hear about all the times when someone didn't put in hardened seats into a Buick head, and the valves burned out and they had to go back in and put in steel seats.

Let's get a consensus going and let the testimonies speak for themselves. :TU:


Gary


Edit: oh and the 455's and 430 I've owned, unleaded in those too. The 430 was a '69, one 455 was a '70 and the other a '72. None burnt valves.

Cleaned up the seats on the '70 455 when I rebuilt it. Didn't look bad at all, just needed a refresh. Put it back together and ran it.

All on unleaded, all with no steel seats.