Help on rebuilding a 73 340

My Aspen I just sold had a 73 340 with stock 587 heads, had the 68-71 stock pistons in it though. Ran pretty good with a MP .497/296 circle track hydro cam, 273 rockers, headers, Holley 650 DP on a Holley strip dominator, 904 trans w/ 3k converter, 3.91 gears. Recurved dizzy and orange MP box. Ran 13.3 on its only trip to the track, no tuning. Drove it 180 miles round trip, I think 12's with some tuning.