You are going to be directed to the RJC head gaskets. I bet you can mill the heads down from 48cc to 46cc. I wouldn't go too much because the intake will need to be milled as well. More work than needed since you can simply turn up the boost! Now if you were to build a new short block you can order pistons to do this without all the milling.
Cometic will custom make you some .027" gaskets. Odds are they won't seal against your used unmachined deck though.
And like mentioned above, shaving the hell out of the heads and running thinner gaskets will require the intake to be milled too. The machine shop costs halfassing a stock shortblock will probably cost more than a set of new slugs.
I'm about to do the same thing. I dug out my original block that spun overheated a main when my car was stolen. I've got all the parts needed to longblock it except a set of pistons. And some steel to start making main caps. For years I've had a mental image of a better mousetrap as far as caps go. I think I'm going to make a high compression ground pounder that'll stay sideways and abuse tires with it.
.....since any money I spend before dec 31 I can write off on my taxes. lol
Yea they ended up perfect and even with the deck . I’m switching to my stage heads so I’m going to have ether get some new slugs or notch these ones for valve reliefs. Idk though im thinking if I notch these I will gain to much volume and my compression will be to low . I’m right at 10.5:1 right now so what do you think ?
Depends on how much notching you'll need. The only way to know for sure is to mock it up with light test springs and see. With any luck all you'll need is a small triangle taken out of the edge of the inverted dome.
With your skills, it'd be easy to convert an old valve into a piston crown cutter. After that all you'd need is a clamping shaft collar to act as a stop. I'm guessing you're lose 1 or 2 CCs at the most.