OP, do you have an LS motor or a Vtec motor? If it's an LS, you can't use CTR pistons. The dome is too high. Also, you need to do some research on your own because until you do, you're going to keep saying you're confused. there actually is some debate on if ctr pistons can fit. Some say it can with a 402 cam but i beleive thats a load of crap.
