I purchased an assembled, 30 over, shortblock with stock internals. I later decided that I wanted to upgrade to forged pistons and replace the middle main caps with billit ones. Would this be just a matter of regapping the rings and checking the allignment of the new main caps or is their alot more to it. I would be having an experienced engine builder/machinist doing it. I've figured the cost of the pistons and caps but I'm not sure of the added cost involved in machining and clearancing. What can I expect? Thanks for any advice

 

main caps:
4 bolt main block? You'll need to align hone the block I think. If it's a 2 bolt block then you may want to machine for splayed 4 bolt caps as well.

pistons: probably need a rebore, or at least professional rehone, forged take bigger piston gaps, like an extra 2-3 thou IIRC.

rings probably don't need to be regapped, if that's any consolation

$160 rehone, $120 align hone, $400 pistons, $200 caps... kinda hard to justify IMHO...

 

Well....it's for a turbo application in a 4-bolt main. Sorry I didn't mention that. Thanks for the feedback