67 Dart GT brake options.... 13” wheels
They're not inadequate if You're still running 13" rims & skins, otherwise You'll probably be sliding the tires every time You get on them too quick! Unless You pick a larger
piston MC to ease the squeeze a little.............
I would not use a larger master cylinder, in a manual brake car I would start with 15/16". Said Cavalier has 3/4" bore and a power booster. Also put an adjustable valve in the rear brakes as you'll probably get some rear wheel lockup.
Disks are less likely to lock at the same amount of pressure due to not being self-energizing. These cars are really heavy for such small brakes, in general a 13" wheel disk brake car is a 2700 lb or less curb weight at 80s standards so maybe with some modern pads they might keep up OK.
I had a 1994 Oldsmobile Cutlass Supreme that has about a 3200 lb curb weight which is like a lot of A-bodies and it had a small-ish 14" brake package and they were barely adequate. A typical car like my 2012 Chevy Cruze at 3075 lb curb weight has a 15" brake package which is IMO where they start getting adequate. And all these cars have brake boosters.
I've had the following brake packages on my own car over the last 17 years:
10" SBP drums all around, manual
10.87 73 Duster disks + 10x2.5 rear drums , manual
11.75 Cordoba brakes + 10x2.5 rear drums, manual
94-04 Mustang Cobra disks front and rear, Hydroboost
The 10.87 and 11.75 worked OK but they don't inspire confidence that much. The cobra brakes + hydroboost are incredible. But I'm far more worried about performance than originality.
