Can it be done??? Low 12's

[Shaggy]

A 351 with a nonlockup convertor your early heads with a good P&P on top of already having the big valves in them and a decent cam and at least a performer RPM and a 700 to 750 holley should get you to mid to low 12's with all the drivability of any good tuned carbed car. In my 67 falcon (same as the mustqang for clearences) i just dropped a 351 in with teh perfomer rpm with a 700 holley and a 1" phenolic spacer clears the hood with a 4" (maybe 3"" need to go measure it forgot exactly but i thnik it is a 4 though) drop center air filter.