Hi Beep , I did a 69 RR with same cam + pistons + manifolds . 727 Auto with 3.55 sure grip . Block decked .020 , pistons popped OUT .010 , and I used 906 heads with Fel-Pros. The heads CC'd around 88 or 90CC's Stock , Had them cut .040 to get to 80CCs. And to use that 272 Cam had machined down the top of the valve guides boss's down from about 3/4" to 11/16 to give me clearance at max lift . I always said it was finally a 10 to 1 383 after all that work . Ran like a Monster . Ronnie