I am planning a light overhaul on a 1978 olds 350 with #8 heads.

My plan was to put a little better cam, smaller cc relief pistons, and reuse the #8 heads. 9:1 would be ideal, if it'll happen.

Anyone know the difference between the 2 rebuild kits? Looking at the sealed power cast piston kit. I'm not sure if it would be any better far as the pistons go.

Also, I am replacing the olds 307 in my 1986 cutlass with the above engine. Can I reuse the exhaust manifolds? Or, they'are small port too. Might put back the CC carb system on the 350 too. Can I gut the 307 distributor and put it on the 350 olds distributor. I believe the roller cam and regular flat tappet cam distributor gears are different.

 

If you want to bump compression with those heads you need flat top pistons, Summit racing has some flat top rebuild kits, flat top pistons for olds start at 400.00. They add add to the cost but it’s well worth it!

 

I think the main difference is the head gaskets due to slight block differences.
And stay away from the cast pistons as they are short on compression height and will result in disappointing compression ratio,especially with large combustion chamber #8 heads. Use forged flat tops as posted above in order to get the CR you mentioned.

 

All 1968-1976 Olds 350 engines are solid main web and use 7/16" head bolts.
All 1977-1980 Olds 350 gasoline engines are windowed main web and use 1/2" head bolts.

FelPro shows different head gasket P/Ns for 68-76 and 77-80. Here's the early gasket (P/N 8171PT1):



Here's the 1977-80 gasket (P/N 8506PT):