what is the intent of the car ? Are you keeping it indefinatly . Personally I would swap to a stock disc set up but keep all the drum parts . I own a 70 R/T SE as well & swapped to stock front disc but then I never intended to sell the car . If you are worried about resale 1st I doubt it would hurt it as long as you have the original parts , or 2nd just leave it alone seeing as it si rarely driven & probably never hard .