I think the main issue with the power boosters would be an engine with no vacuum or that the ones for these cars have too much boost.
In general a booster would help you get more pressure out of the brakes, which would increase your ability to brake up until the point of locking. I have seen some dual diaphram booster kits on EBay, however, I have not seen anyone actually running them for feedback.
Due to the way the booster mounts for these cars, there really isn't much of an application where you could just junkyard swap it.
Not sure what you are asking. There is nothing really new in the general physics of brakes. Some materials have improved. But the principles are the same and the old '73-'76 setup is pretty good.
- ABS in everything is the only thing really 'new' in brakes (but actually ABS existing 30 years ago...)
- The newer large brakes have an advantage in heat capacity but that takes large wheels and do you really use your brakes all that hard?
- Multi-piston calipers have some advantages but really only are needed in very hard use.
- Rear discs add heat capacity, but the brake power that you can put in the back is limited by what you have up front, and the 10" and 11" rear drums have plenty of brake torque as they are. Drums don't like water in them, so rear discs would be good if you drive in a lot of deep standing water.
If you want anything better that you would feel for sure in daily driving, then you might consider using braided teflon soft lines rather than rubber. They do not flex/swell as much under pressure and you get an ever stiffer pedal and more precise brake modulation. And using better CoF (coefficient of friction) pad materials will improve stopping power, but going with much higher CoF pads up front with the 10" drums may put too much brake torque in the fronts and you will be out of balance without going to a different rear shoe lining.
Hope that answered what you were seeking.
I've worked in brakes for the last 11 years with the OEMs...There are certainly a few reasons to want some stuff beyond the 73-76 brakes. They are adequate but not really earth shattering (and I have the 11.75 front rotors).
The heat capacity could improve IF you have the larger rotors, but same sized ones from now vs the 73-76 have similar heat capacities...in fact these older rotors have significantly more iron so they are less likely to have judder issues. But the rotors aren't the main issue.
The calipers would seem like on paper that they would have really high capacity being such large pistons but the combination of very few pads with any type of friction coefficient rivaling todays brakes and their quite high slide force make them less than ideal. They also seem to have really high drag torque. I'm not sure if you're referring to "multi-piston" as only being opposed piston stuff like wilwood/brembo or the pretty basic twin piston jobs like you'd find on a basic mustang. The twin sliding caliper with a modern pin setup would be a real good setup for this car. If someone did a bolt on for an 11.75 rotor it would be a great kit to have for a general hobbiest. The twin has better force distribution, especially across a large-ish pad.
Rear disk brakes are great for another reason - they don't have the tendency to lock cold and immediately on a hard brake apply like you get sometimes with drums...and they can be modulated linearly.
If you don't mind larger (17"+ wheels), the Doctor Diff Mustang Cobra kit is a great option. If you do want to keep 15's and want some rear disks he has a kit that will work there too.
I wish we could easily retrofit ABS with Electronic Brake force Distribution to these cars. With a little tuning the car would be able to stop shorter and work better on different surface conditions.
