No alternator likes being maxed out for long periods of time. Charging Battery with Alternator - Warning
Heck most electric equipment has far less than 100% duty cycles.
The weakest connection on the OP's '74 is probably the alternator output terminal connection at the bulkhead.
It's has the terminals with the least surface area in the circuit, minimal airflow for cooling, and all of the current is passing through it. At the mainsplice the current divides so everything downstream of that sees less current through it.
My biggest concern, and I guess 67dart273's too, is that the VR is not regulating.
