oldzy

Just wondering what the stock compression is on 1970 350 4bbl.

I want to eventually rebuild my 1972 CS 350 4bbl closer to 70 specs. Changing pistons all that is really needed? Does the 70 use similar type dish style pistons?

I would like a little more power w/o going overboard, and still be able to use the A/C, have a slightly bigger than stock cam, etc.

1969w3155

10.25:1, the dish on the '72's are deeper. You could get a mild cam that closely matches the original specs. or go slightly more aggressive with the modern grinds, and easily run a/c with no issues

507OLDS

The 70 engines used a piston with less dish,compared to 72,so that is where the compression difference is.The CC's of the heads are the same.You could reuse the 70 pistons into your 72 350,as long as the pistons are good,& your cylinders don't need bored.If they do need bored,you can get aftermarket high-compression pistons.

oldzy

I would prob get aftermarket pistons. Are the flat top 2320 Speedpros the ones I would want to get close to the 1970 specs? I don't want to have to add a big cam, or drastically change the torque converter/rear end gears either for example. I will be adding a 3.42 posi eventually.

I royally screwed up my last rebuild... HMV-272-2 Crane Cam, stock deep dish pistons, RPM intake, stock 2.73 gears... I had to put the pedal halfway down before the car would move. Like a really bad clutch or something.