273 commando Build

I've built more than a few HP 273's with Fel-Pro 8553 PT head gaskets. Used stock head bolts torqued to 85 ft lbs and never had blown a head gasket. 273 heads, 57.4 cc chambers, or small valve "J" 340 heads 65 cc chambers, TRW forged 10.5 pistons and made more power than you. Those 273's would take everything a 600 Holley, "67" AFB, and a "71" 340 TQ had to offer. Hate to tell you, but I'm pretty sure your block needs a minimum cut for the decks to be square and equalized. See posts 237 and 240.