i've got a friend with a third gen camaro, he had a shop do the machine work on the block, he put together the short block, bought some used world iron heads that we're supposedly fresh from the machine shop too... put it all together, started it, said it ran for a few minutes, popped and steam poured out.... it's leaking from the head bolts which are arp... he tried some permatex thread sealant and is still having the same results.... any ideas???

worst case but maybe a head gasket is bad or the block or one of the heads is warped and/or cracked, perhaps?

possible that the threads let loose in the block? i know they don't protrude into the water jackets sounds like either the head gasket let go,the block is warped,(not decked sufficiently)warped head,crack in the deck surface?