As i found out to my cost, my old 440, stock 6 pack rods, 6 pack pistons, ported iron heads, then later edelbrocks, Crane R280 Roller. Revved it to 7000 trying to get in the 10's, spun a bearing and a rod exited the sump.
New 440, smaller flat tappet cam, better recriprocating assembly, more comp, old heads int and carb, time in sig and i think there's maybe a 10.1 in the car, shift at 6200 trap at 6500.
Mick