I have always used 455's and love their power. I try to squeak by the cheapest I can and from one Buick big block builder that I have known from the Kenne Bell days he says I'm lucky. I have two 72 Buick Skylarks and one of them is for sale and I always tell them in the add if I keep working on it the price goes up. They both have 350's in them one is suppose to be a 68 4 barrel I havn't check the numbers and the other was supposed to be a rebuilt 350. I checked the numbers and on here the guy from over there said it was a 77 and thanks for your help. I pulled the heads off the 77 and guess what I found? .040 pistons but the dish looks deep. I was thinking about puting higher compresion pistons in it, polishing rods and balancing assembly. But I don't want to spend alot of money that I don't have so that is what the build depends on. I have had some good advise from a couple of guys on here so just want to let you know that I appreciate it and let's keep working together on this and see how fast we can make a 350 go naturally aspirated with little money. Here are some pics of the teardown so far.
I would take the short block apart, clean it up and put it back together if everything checks out. Then I would either swap the 68 heads on or find a set of 68-70 heads. They are easy to find for low cost around here anyway. Because the 350 has an open chamber head design it is not as critical to get a zero deck for a good quench. I advise just removing a lot of material from the heads to get your compression up. We have seen about 400 HP with just 9.5:1 compression as the power is in the head porting. Find a poston intake, make it a single plane by removing the center divider and have some fun. Have a look in the alum heads thread for more info on the poston intake idea. The 77 block can use any year heads without any mods just be sure to match the lifters, pushrods, and rockers with either the 68-69 system or the 70-80 system for oiling the rockers.
I just checked the piston to deck clearance and wow the driver side has .110 and .113 and the passenger side has .109 and .107 so that shows how far down the pistons are in the block and how uneven the block is if the rod and piston length is the same on those 4 cylinders. I will check that when I take them out.
Yes, I have had to square off the blocks decks as I have seen the same thing. Some aftermarket pistons have a lower than stock compression height.
Just got the bottom end plastigauged and pulled apart and good thing I did. The rod bearings had a couple that look like dirt or metal got on ther bearing from the feed hole. and they were all about .0015 clearance so that's nice for stock but I would rather have .002. The mains were around .002-.003. But I noticed 2 of the cap bearings were on the wrong caps like 4 was on 5 and 5 on 4 which makes them off centered in the caps. Has anyone else seen this? Does anyone use fully groved cam bearings and main bearings?
I use the TA grooved cam bearings. I have added a partail groove to the block behind the main bearings and drilled 2 holes in the bearings to get oil to feed the journal from these new holes. Yes, the caps need to go back where they should be or issues can come up.
The caps were in the right place but the bearing insert is offset on 4 and 5 and they were switched causing the bearing insert to hang off 1 side of the cap.
How do you make a poston intake into a single plane intake? I have a poston and mite consider doing it since I have access to a milling machine.
I did it ....it's really not that hard. If you cut the center divider out and then clean it up it would work. I then added a 1" spacer to increase the upper plenum and then port matched to my ported heads. It really works well in the upper rpm range as long as you have the supporting parts. If you look through some of my posts there are some pics....pm me if you would like some more info http://www.v8buick.com/showthread.php?239729-580-HP-NA-Buick-350-that-raced-the-circle-track/page2
The casting numbers on these heads I pulled off are 1243452 and it looks like the valves are almost touching. I don't see how you would ever get bigger valves in there. I will try to find the casting numbers to see what year they are. ---------- Post added at 10:02 PM ---------- Previous post was at 09:53 PM ---------- Looks like 76 or 75 by Gessler site it says large chamber so those have more cc's than the 68's?
I have never measured the cc on the later heads since we knew they were no good for performance. They may well have larger chambers although I am not sure since it would put the low comp engine down even further past about 7:1. With the 24 CC dish and piston WAY in the hole you are really low already. All the more reason to swap on the 68 heads but mill them down a bit first to up the compression.
Those mains are close to .003 I'm thinking about line hone to tighten them up to .002 and the rods are .0015 taking some off the rod journals to get them to .002. What do you think about .002 across the crank?
The actual effect on your car in the low RPM will depend on things like the gearing, camshaft, tire hieght, etc. If the car is set up for high RPM already then the single plane will only help the car. If the car is stock the single plane will hurt the car off the line likely. ---------- Post added at 06:25 PM ---------- Previous post was at 06:23 PM ---------- Not a bad idea. I have good luck with .002 on the mains and .0015 on the rods so I can say it works well even shifting at 7000 RPM.
Also measure the valves on the heads, maybe someone already swapped in oversized valves. The 76 heads should have the oversized 1.55 exhaust valves stock. The early heads had smaller exhaust valves but still perform better.
you will definitely lose some bottom end so as sean stated above your going to need gears and stall to overcome it all. I can say that I am happy with mine although if you plan on daily driving the car you might not be happy. In my 70 heads as I remember there is only some like +/- .020 between the valves after the larger valves are in 1.92, 1.55 and now I have the chambers at 52cc's along with the porting.
Another thing that oil pick up hole in the block where the tube mounts looks like 7/16. Isn't that kind of small for oil flow?
Interesting thread, I too only had big blocks up until recently. And like many of us, money is tight. I have about 900.00 in a 70 350 from a GS. It had sat in a garage for about 12 years, ...had been whooped most of its life. Had been apart a few times, there was piston skirts and pushrod pieces in the pan, the pickup was nearly covered in sludge. But the block and crank were nice. I got some EGGE pistons, T/A' s version of the Hemi killer cam for the 350, bearings, etc. honed the cylinders and then just cleaned up the heads, replaced the seals and valve springs. Never dyno'd or even been to the track but it sees daily duty and has been together for a year now with no issues. Seat of the pants it pulls pretty hard through a 200R and 2:73 rear. Fed through a 670 cfm holley street avenger and a ta intake. In a 81 Century Wagon too...
