340 Piston to valve clearance w/RHS heads

Yeah but he isn't going for 7000 rpm max power levels. Its just a strong street build. He is going to leave power on the table.

I agree Mopar played it too safe, that is how things were done back then--too safe was better than not safe enough. Those old pistons were loose at 100,000 miles.

These newer pistons are much better than the old trw's, he should change the pistons, IMO. 9.5-10 to 1 compression is easy with 63 heads. In fact he might be closer to 10.5 to 1.