I've did some searching here but didn't see my situation . Ok im gong with 4 wheel disc set up . Fronts are 11 inch with Wildwood racing calipers that came with the Superide front suspension . The rears are off a Mark or a Explorer and measure at 11 1/4 inch . Im going to try and fit a 94 Mustang disc disc master with booster on the car (with the clutch brake pedals ) . Will i need to add a proportion valve and or residual valves to this app. I think it would have been better if rear were 10 inch right then it would equalize a little better. The weight class between the two cars aren't really that far off giving some great braking hardware .