Me and my pops, is building a 355 twin turbo camaro with a 300 shot. We have forged internals, pin-point balance on the block and internals. Dish-top probe pistons which are froged and Dart Iron Eagle heads which have a 3 angle. we have ARP head studs and will run a thick head gasket to decrease combustion allowing more turbo boost. my question is...How can we determine the total combustion chamber size since we dont have any paperwork on the heads and pistons due to a fire damage. 
the crank is a regular 350 crank and the pistons have a four valve release in top along with the dish-top. if the cam size matters also, well we dont have that because we need to figure out the combustion to determine the lift and duration we will need to run.
These articles explain how to accurately determine compression ratio much more thoroughly than I could, given the limited amount of space Yahoo! allows in the Answers format.
http://www.chevyhiperformance.com/techarticles/46778_engine_compression_guide/index.html
Basically, it's the amount of space above your piston when it's at the bottom of the stroke, divided by the amount of space above your piston when it's at the top of the stroke. Sounds simple, right? LOL
Probe Pistons Forged Dish 4.030" Bore Ford Set of 8 12360-030, Probe Pistons Forged Dish 4.060" Bore 5/64" 5/64" 3/16" 1.562" CH Chevy, Probe Pistons Forged Dish 3.840" Bore Buick Set of 6 14477-040, SBC CHEVY 350 FORGED DISH PISTON SET 4.040 X 3.48 X 6.0 X 9.66:1 with 64cc HEADS, SBC CHEVY 383 FORGED ROTATING ASSY. 4.040 BORE -22 CC DISH 1PC.RMS, Probe Pistons Forged Dish 4.030" Bore Chevy Set of 8 P2441F-030, Probe Pistons Forged Dish 4.030" Bore 1/16" 1/16" 3/16" 1.090" Comp. Height Ford, Ford 302 Probe FPS Forged Dish Top -12.2 Pistons+Rings, Probe Pistons Forged Dish 4.030" Bore Chevy Set of 8 P3832F-030, Probe Pistons Forged Dish 4.060" Bore Ford Set of 8 10676-060, Probe Pistons Forged Dish 4.350" Bore Chrysler Dodge Plymouth Set of 8, Probe Pistons Forged Dish 4.350" Bore Chrysler Dodge Plymouth Set of 8 12499-030, Probe Pistons Forged Dish 81.50mm Bore 1.00mm 1.20mm 2.80mm fits Acura, Probe Pistons Forged Dish 4.440" Bore Ford Set of 8 12330-080, Probe Pistons Forged Dish 4.155" Bore Ford Set of 8 14717-030, Probe Pistons Forged Dish 4.060" Bore Ford Set of 8 12360-060, Probe Pistons Forged Dish 4.530" Bore Chevy Set of 8 14807-063, Probe Pistons Forged Dish 4.030" Bore Ford Set of 8 14848-030, Probe Pistons Forged Dish 4.030" Bore Chevy Set of 8 12344-030, Probe Pistons Forged Dish 4.390" Bore Ford Set of 8 12331-030, Probe Pistons Forged Dish 4.155" Bore Ford Set of 8 14432-030, Probe Pistons Forged Dish 92.00mm Bore Subaru Set of 4 14491-STD, Probe Pistons Forged Dish 4.000" Bore Ford Set of 8 10668-STD, Probe Pistons Forged Dish 4.125" Bore Ford Set of 8 14717-STD, Probe Pistons Forged Dish 4.000" Bore Chevy Set of 8 14910-STD, Probe Pistons Forged Dish 4.030" Bore Ford Set of 8 12350-030, SBC CHEVY 383 FORGED ROTATING ASSY. 4.030 BORE -22 CC DISH 2PC.RMS, Probe Pistons Forged Dish 4.030" Bore Ford Set of 8 10668-030, Probe Pistons Forged Dish 3.582" Bore Ford 4.6L Set of 8 10178-030, Probe Pistons Forged Dish 4.040" Bore Chevy Set of 8 12344-040,
