Discs vs drums.

Where discs shine is in fade and water resistance. Today's cars tend to run seriously undersized rotors with aggressive pads, which is why rotors don't last anymore.

Dry, first time stop, drums can actually out perform discs due to their self energizing capabilities.

Since this is a "resto" you aren't still running skinny bias plies are you? Any brake system is limited by traction. If the brakes are locking up adding more brake will do nothing. If the brakes do not lock up then you have a brake problem.

All that said, I prefer discs and you have more options in regards to pad aggressiveness. I tend to run the factory based 11.75" setup for several reasons. It's cheap, it is well engineered, parts availability is great.

So, are you current brakes capable of locking up the tires?

They say there are no such thing as a stupid question.
They say there is always the exception that proves the rule.
Don't be the exception.