[Z15 SS 454]

Ok, Loaded question here and i will try to answer it with a few questions

1-You need to decide on compression ratio that you want (cc volume of head chamber,head gasket thickness and choose dome volume of piston )

2-You need to choose a cam and mock up short block to check valve to piston clearance.

3-There is no set up that you can buy that will guarantee no valve to piston interference due to the following inconsistencies,Deck of block machined to "zero",Cylinder heads machined many times for straightness,cam shaft timing (580" lift cams can have enough overlap to crash pistons),head gasket thickness and a few other things to consider.

Keep in mind that if the pistons say they are 11to1 the true engine compression is not 11to1 due to above stated variables.

Sorry for long post but hope it helps.