conv90

Pistons: Compression ratio differences.

I‘m searching the right piston kit (stock like) to use for my rebuild. My car is a convertible 1990 A/T .
Stock pistons are flat with 4 v. relief no dish .
Searching for catalogs I see the Sealed Power Hypereutectic H345P listed as Flat w/ 4valve relief.
In all catalogs the price range for the set is $75/ $90 and the compression ratio (with 64cc combustion chambers volume – the 64 cc data is allways present on pistons data, the 58 cc it’s a rare data…- ) is allways some thenth lower comparing with others flat pistons w/4 valve relief. H669 P (Fedral Mogul group also.. I think they are Speed Pro) are also Hypereutectic machine worked flat top pistons w/4 valve relief, but are rated 0.2 / 0.3 higher on compression and are $100 / ख़$120 higher in price!
The Question: H345P are lower in compression ratio for larger valve relief? Or these pistons are lower in C.R. beacause they (maybe) are deked 0.025” / 0.030” under cylinder deck? I don’t want pistons with deck gap if stock pistons are not…. (I don’t know if stock pistons are deked or not).. Can I consider H345P a standard replacement of my stock pistons?? Someone in the forum used thhese pistons?
Another technical question: If I use for my rebuild a Forged piston kit ( TRW /Sped Pro forged, Flat with 4 valve relief) which is the advantage instead a cast /hypereutectic??
Finally…. Last question… Could I utilize a flat top w/ 2 valve relief??

Thanks
Beppe

conv90

TTT

conv90

Ther's none that can answer to my questions?
Beppe.

conv90

surrender.... none know..

VQT88Vette

Try the Engine Mod section, people there might have the answer.