well i got my heads back friday and the machine shop couldn't find anything wrong with the rh head, even though i know i saw #6 shoot alil water out when i water pressure tested the motor, also #7 shot out some. well he said he found a exhaust guide leaking on #7, fixed that but couldn't find anything wrong with the other head. so i get home friday, wait for it cool down, go out and start cleaning up the block to slap heads back on, on the rh i see that #6 has a thin sleeve in it, immediately i know where the water got into the cylinder at. rotated the motor till the piston was down, and sho nuff, a 6in crack in the bottom of the sleeve when the block got air exposed, rust highlighted the crack for me, never saw it the prior weekend when i took the heads off. i had my 10yr old yank the shortblock back outta the boat and once he had it hanging , we stuck it on a stand and busted the block down. found that the bottom end was fully balanced had arp waveloc rod bolts on dimple rods, with forged 10.5 to 1 pistons(which still look new). not sure but the crank looks to have been nitrated, cause its black, but the p# on it show's to be 454 cast anyways, someone knifed the throws and did a shitload of work to a cast crank. i've got the block in my blazer, i'll send it over for a thick sleeve after lunch cool the bottom end is balanced though!