which kbs???
ok but if i get kb107s and i dont have a 72 cc head and its less or if i get a thinner gasket that raises the compression
You said you had stock 76 heads so unless there has been machining done to the deck on the heads they are not going to be 65 cc's typically they are around 72cc's.
If you want 9.5:1 compression you will need to take the engine apart and measure the deck height and you will need to cc the heads then you can calculate where you need the pistons to sit in order to achieve your compression ratio. Because of the variables when these engines were built no one can give you a shopping list of parts that will go together everytime with the same results.
If you don't have the means to make the measurements yourself the best bet is get the block and heads to a machine shop and tell them what you want to accomplish and let them tell you what machining is necessary.
You also mentioned using the KB232 piston. This piston is intended for magnum engines and you will need to have the small end of LA rods narrowed to use them.
I would suggest that you use magnum heads (typical 64cc's) for your build. The KB107 at zero deck, a 0.039" head gasket and the magnum head will give you 10.6:1 compression. I have this set up with an XE268H cam and it is very detonation resistant with the close quench magnum head. It will run on 89 octane with no audible detonation. If you go with the KB232 piston at zero deck and the magnum head you will have about 9.2:1 compression and might actually get away with regular 87 octane gas. But that XE274 would sure like the 10.6:1 compression.
NOTE: I chose the XE268H came just because the step up to the XE274 required a much stouter double spring and since my car is strickly a street car I didn't want to take the hit on valve train longevity you do when you start using really stiff springs.
