I have a 1973 Cutlass S with a 403.

I am looking to upgrade the quality of the current brakes (F-disc/R-drum currently). I will stick with the current approach of disc/drum —Can anyone make a brand recommendation and source for parts?

 

Are you wanting info on better quality pads and shoes or info on better calipers? I don't think there is much out there for upgrading drums.

 

Your car currently has 11" front rotors and should have 11" x 2" rear drums. The steering knuckles have integral caliper brackets, so you can't change the rotor size without going to an aftermarket brake setup, which entails cutting off the caliper mounting ears and adding a bracket.

While I have not tried this, you MIGHT be able to swap to the front spindles used on the 1977-1990 full size wagons, which have 12" rotors. The stock rotors on those cars have a 5 x 5" bolt circle, but you can get the rotors from a third gen Camaro with the 1LE brakes that are 12" with the correct 5 x 4.75" bolt circle.