i got a set of forged pistons for a 400 sbc i got .030 over. has a small dome. i already looked up the number but its not coming up. so i dont know.. so i was going to put motor together and measure it. ive never done this before but remember hearing people talk about it so figure it would be a new lesson.. i was going to get a peice of thick plastic from work and bring in a old head gasket and make a peice the size of the one cylinder and id drill and conter sink the bolts and drill a whole for the cylinder to mic the cc with.?? how far down do i have to go and what else do i need to do or know. thanks..