I am rebuilding a 350 for my '86 iroc/tpi. I will be using shorty headers (already have them) and an L-82 cam. The block doesn't need to be bored. It has dished pistons in good shape. Using 882 castings heads. Would it be worth it to go to flat-top pistons? How much gain would there be? I know it would be better, but how much?
Thank you for your help.
Ignore my signature, the 406 is broken.

 

Dished pistons and a 76cc chamber is a recipe for really really low compression. Especially if you're not decking the block. Depending on the size (cc's) of the dish and the height of the deck, you might be in the 8:1 range.

Yes, it's recommended that you switch to flat tops (if you're stuck using the 882's).

Personally, I would invest in some different heads before flat tops. 882's being the smogger, big chamber, thin prone to cracking crap. Now if you switched the 882's to a 305 head like the 416 casting, which has a 58ish cc chamber, you'd be around 9.5:1 compression.

 

Yeah why the 882 heads? That's your problem. Get some good 58cc heads.