455cutlass1969

I have a set of 396 Chevy pistons that are for a. 020 overbore. The stock bore for 396 is 4.094 plus the .020 overbore will be 4.114. Will that work in my stock 455; 4.125 bore? I can get the rods bored to match the Chevy pins and mill the domes flat. Should be at least 10:1. Will the. 020 work? Can I use what I have?

J-(Chicago)

too small. mic your pistons.

krooser

Won't work... and I would bet the compression height on the Chevy is pistons different, too...

joe_padavano

This is why you should have stayed away in math class. That's a 0.011" difference between the piston and your STOCK bore, assuming no wear. Forged pistons want 0.0045-0.005 or so. The compression height is close (1.78 vs 1.76) and the rods can be bored out for the larger Chevy pins, but you've still got way too much clearance.

455cutlass1969

Could I go 030 over? That's 4094 at 030 is 4124. That's pretty close to 4125 stock...

61reoldsman

You need to find out what bore the block needs ,.030,.040 whatever then order the pistons to match ,using Chevy pistons requires some more math to fit .Go read the stroker posts on the small block forum side to find the proper calculations necessary to put a Chevy piston in a
Oldsmobile hole .Good luck

455cutlass1969

Cylinders are round true and honed. I just am seeing if what I had would work or not. I may have to go 030. This should give me around 11 to 1 compression using a thin head gasket. That much duratiom is olay for 93 octane. There is enough overlap. There is a build on this site that is similar.


http://www.442.com/oldsfaq/ofe455.htm

455cutlass1969

I meant to say my cam is at 260 @ .050. Stall 3500

61reoldsman

If your using an iron head that much compression is going to be a problem.

cutlassefi

Just curious, is that a solid or hydraulic cam?
I guess it doesn't make any difference because your direction doesn't really make any sense to me.