iam planing on building a 398 its going to be .060 over ,going in a pick up.rods are 6.200 C/H is 1.355 .do i have to notch the block ,like you do a 408. this is my towing truck. plan on running dish pistons to get compression down.right now i'am running 10.7 to 1 with rpm heads ,want to run reg pump gas.i think i need a -30cc dish ,going hyper pistons,anyone got a good link to a kit. cheapo ones ok! thanks