I am doing or at least I am wanting to do an ls/vtec conversion and I want to go with either the P30, ITR, or CTR pistons. I was wondering if there is a drastic difference in piston mass between any of the vtec pistons and a PR4 (stock) piston? I ask this mainly because if there is not too much of a difference in piston mass, then I should not have to get my rotating assembly rebalanced. Yes, I do realize that vtec pistons have a huge dome, but that doesn't tell me whether or not there is less material on the piston in other places such as around the wrist pin bosses, etc. I really need to know the piston weights.