Magnum Heads
Yes I was aware of the cracking issues.It seems to be worse in the pre 99 heads.
I got lucky and found a pair with no cracks right away.
My stock heads chambers measure right around 63 cc.Is there that big a diff in castings?
Sounds like your app is far from stock,judging from the mods.
I thought chevy locks would work??Seem to remember something about LS6 locks being 8mm..