Riddle me this....

That’s a master for disk drum combo.
You are right but I've also ran a disc/drum master with 4 wheel disc with no problems.
What bothers me is The way that it is mounted, he barely has room to put a battery in the car.
No offense to the OP but what a crappy design that is...A stock 73-76 A body setup would be a much cleaner, compact setup.