Help with 340 compression + cam change

Pistons are the old TRW L2385 stock pistons for the 72-73 340s. (Lower compression motors) Four valve reliefs.

From an old Moparts forum post:
“Compression height 1.591” (vs 1.74” for the hi compr. 2-valve reliefs) ...and allow 8 or so cc’s for the 4 reliefs.”