It's this cam:

Duration at .050" lift: 230/236 (int/exh)
Valve lift with 1.5 rockers: .488"/.491" (int/exh)
Single bolt, high performance street, very strong mid-range, 2200+ stall converter.
Comp Cams 21-224-4

Given 6000 rpm, but what's to expect?
We're in doubt of 3.55 or 3.91. I lean to 3.91


72 challenger in resto. 493 super-engine!