Any guidance on my 1970 Duster plans

Like said, sell the TA motor to a collector, and pick up a 340 and build it. That is the smart way. Put that TA motor in that NON TA or AAR car, and what you have is 1. the value of your slant roller 2. the value of the TA motor. Add them up and you have mostly what someone will pay for the TA motor.
I know, YOU will never sell any of it!