I have the 1 1/32 master cylinder with the first generation viper calipers kit.That is the mc diameter that the instruction sheet suggested when i bought the kit.
I have manual brakes.Although the pressure on the calipers arrives to 1500 psi,the car does not brake well.
Not good brake feeling,the pedal is very hard and i,m not able to lock the wheels.

Searching the forum i have read something about the 15/16" master cyl from Doc Diff.
Will the difference with the 1 1/32" worth the 100$ or more that they ask?

I also have 255 mm diameter drums in the rear with 15/16" wheel cylinders.

Thanks a lot