I bought one once thinking it was the problem and it wasn’t. Kept it in the top drawer of my tool box for over twenty years. Might still be there.
Currently 2 of my boys own 1 77 slant six Aspen, 1 80 slant six Volare, and 1 318 v8 77 Aspen all with ballast resistors and none have blown since I picked up the first Aspen for one of them in 2001.
Miracles do happen ;) I wonder if it could have been partly a materials issue. Chrysler had a lot in common with Lucas Electronics back then. Lords of Darkness...