keep saving your money if its going to be a few years down the road options on heads and rotating assembly may change or you may decide to go a different route down the road I spent a few bucks on custom 360 pistons and about 9 months later several companies had a shelf piston for less or the 6.125 chevy rods I got only to have 6.123 eagle rods suddenly go into production from my experience wait till you ready to build your project before you buy parts things tend to change