For a track only car I'd start looking for a running 440/727 combo out of a C body or motorhome, if it runs good throw in fresh rod & main bearings, MP .509 cam and springs, RPM manifold w/800-850 DP and 2" fenderwell headers, we ran this combo in a friends 70 Dart for years with a 10" TA converter and 3.91's w/26" slicks. It would run 11.60's on motor and 10.90's with a 125hp powershot fixed plate.
It was an untouched longblock except for the cam/springs and had 95-105psi cranking psi.
The current motor is a 446, ross flat tops 0 deck, 915 heads w/2.14/1.81's, 284/.528 solid, RPM intake 850 DP, pro parts headers and 3" exhaust, same converter and gear, 27" radials and runs 11.0's@121 on pump gas.