No spark

Combo
1...Bulkhead connector terminals were never designed for over 20A. I used to service HVAC/R and the similar 1/4" "flag" terminals are/ were used universally in electric furnaces, which typically draw 20-25A per element and THEY FAIL
2....50 year old wire crimps at terminals

3...Wire size is small for anything over about a 40A alternator

4.. Ammeter has several problems depending on year. Worst were the later cars with plastic cluster housings. If the studs/ nuts get the slightest bit loose, the plastic softens and then they get MORE loose. The studs are not soldered/ crimped / or welded to the ammeter "guts." They just slip through and depend on the nuts to stay tight...and they don't. Add up compression of the fiber insulating washers over the years, and "we have a fire"

5...Then us kids come along and stick larger alternators on 'em and Great Big fans, pumps, stereos, etc