Hal , just don't forget to go to a disc/drum proportioning valve. Without this you will not hold residual pressure to the discs and have very poor front/rear brake bias (read; hang on to your butt in a panic stop).My Gremmie is set up with the discs from my old Matador and the mc and proportioning valve from the same donor car,rear brakes are drum from a 69 GTA Mustang as is the axle - i was going to go 4 wheel disc but found no need, this set up stops this car from a 100 mph plus with no problem,didn't even have to go to an adjustable prop valve. -Vik