Hey y'all, I put a Pertronix HEI in my '72 bronco 18 years ago. The vacuum advance is shot. Since the base is Ford but the Cap is Chevy, does anyone know what year or part# I should be looking for as far as Chevy's go. This is my first time messing with the distributor. Trying to replace the vacuum advance first before moving on to other diagnostics. Any input is greatly appreciated.