So working on my 70 Skylark and its getting there I am thinking of the next stage of restoration drive train upgrades. So my cousin gave me a 73 455 missing rockers, intake, distributor, and some other odds and ends. Option 1 is budget minded with hone the cylinders, new bearings, gaskets, rings, and run it. Option 2 depending on budget my ideal setup would be 10 to 10.5 compression and a fairly mild cam 220-230 at .050" q-jet, probably manifolds since the headers I have seen seem to break the bank. My question is should I just run my heads, put stage 1 valves in my heads, find 67 big port heads (I think I know where a pair are). For pistons can the stock pistons meet my dreams or will I need to buy new ones. The car will probably be mostly street driven and fun times at the drag strip. Will keep it pump gas friendly, my Camaro is a 454 with 10.25 compression and 240/246 cam and I don't have any issues with compression but the cam is a little much since the springs need to be so tight and its a little loud.
Here's food for thought back in 1985 I was working at a Buick dealer and I picked up a 73 LeSabre with a 455 had 90,000 miles on it I rebuilt the motor in my parents garage. I Honed the cylinders New rings I didn't even gap them a new bearings I installed the KB 118 cam had to stock small valve had rebuilt stock iron intake. headers an use the carburetor off my 70 Stage 1 and fuel pump, installed it in my 71 Skylark stock turbo 350 trans had a 293 Posi out of a 70 skylark car went 13 60s at 101 mph on street tires. Would finally shift into third gear going through the lights.
If a cast piston goes south it will take the whole motor with it if Murphy's law holds true ,if you get real lucky you will just crack out the Pistons inbetween the top and second ring groove which will only tare up the cylinder! Forged pistions are lighter then cast and many times they have lighter pins so the motor will rev faster and that will make for a good performance gain just from that. The fact is that not one GM cast piston from all of there car lines was every made to deal with 400 hp ! Head wise your should go for the bigger valves but get them in the 11/32" stem size and have all the 16 valve guides replaced to run that smaller size stem. On the Exh have a 2 angle valve job done 45/60 to leave you with a nice wide .075" seat , and the Exh porting wise open up the bowl exit to the runner on the sides and roof by that same increase in valve size. This minor porting work should take 5 minutes per port. If your running stock Exh Manifolds your should spend time to get the carbon and rust scale out of them as during flow test I have seen as much as 8 to 10 cfm of Exh flow per port drop off due to ruffness !
With the aluminum cylinder head options we have today, I would not bother converting small valve heads to Stage1 specs. You are so much better off saving that money and putting it towards the purchase price of a set of aluminum heads. They will out flow most if not all iron heads right out of the box. The overwhelming majority of the power producing potential of these motors is in the heads. A little delayed gratification is a good thing here. JMO.
The problem for me is that I look at aftermarket heads and they start at 1500 for bare Buick heads. So my thought is that I could put that much into my heads and probably be ahead and have a sleeper look and if I do the porting myself that is more money into something else. I have also heard you shouldn't just bolt on aftermarket heads they need to be checked over and maybe a valve job. Also I heard the edelebrock heads have some other issues. Another thing is that I have several machine shops around me probably because of all the dirt tracks. I will most likely go the budget route, but if I do decide build it I will see what my options are for forged pistons to keep my options for later upgrades.
If you can do the porting yourself, that will save you a lot. I still wouldn't bother with the bigger valves unless you can do that yourself as well. Just port the small valve heads. The TA heads will outflow most if not all max ported iron heads. The only thing you need to know about the Edelbrock heads is to NOT buy them assembled from Edelbrock. Their valve job leaves a lot to be desired.
Maybe, some of them have bigger ports. http://www.v8buick.com/index.php?threads/67-430-big-port-heads-worth-it.336779/
build it to fit your budget, not what other s want you to spend, (unless they wanna buy stuff for you!) cast pistons failing at 400 hp? BS! ( yes, they are NOT a race piston, but factory rated at 360 hp) so your saying they will not handle 40 more hp? I too have limited $$ to invest, so I think of the whole package, and possible later improvements, then buy wisely, and economically. too much cam is the biggest mistake everyone makes, anyway you do it, let it be fun, and enjoy it,
So here is my current thoughts, I found a 67 430 with th400 for 500 bucks. I need an intake, valve covers, rockers and shafts, exhaust manifolds, flywheel, and a torque converter. So if I were to buy them one at a time even used how far away from 500 would I be and would it be worth the extra money to have some spare parts laying around.
Brandon if you have a running vehicle and a separate engine to build then take your time and piece it together slowly. I myself have a 72 455 (built by some one else) in my car that is running and I am enjoying it but it's not exactly what I want so I am building a 70 455 slowly. I have more time than money so I will just buy pieces here and there. The luxury of having more time than money is it gives you the opportunity to educate yourself and plan your build EXACTLY how you want it to be. This site is so rich in knowledge for so many build types that you can easily get caught up in it and get side tracked from where you wanted to be. My 2 cents is spend the money on the internal parts bearings, pistons, oil mods, cam, ect first and use what ever bolt on parts you have. That way you can ad better heads, intake, headers etc later on and you don't have to tear back into the motor to change anything, just add to it as money permits. What ever you do come up with a build plan and parts list and and stick to it or you will have tons of parts laying around and money spent with no engine to show for it.
I'd wager that issues with cast pistons come from people rattling them with not enough octane. When I tore down my GSX motor numerous pistons were cracked as well as rod bearings pounded out. The guy was a cheapskate and probably ran regular gas. Then again towing a trailer and trunk full of rocks across the country didn't help... He wasn't even a Buick guy....just thought it would be good to haul with and believe it or not the dealer made him a great deal on it.....they were having a hard time selling it out of the showroom....people would buy a reg GS or Skylark after looking at the yellow GSX, I suspect...
