Ok so I finally got around to installing the rear disc set up using K20 calipers and rotors. After driving a few days I love it so far. The pedal is perfect and at least unloaded the brakes are so much better its crazy. The only thing I didn't do yet is remove the residual valve from the master cylinder. I have been reading that it is usually a 10 psi valve. I know that it will possibly make the calipers drag but is 10 psi enough to worry about? Or just drive it the way it is? Also I have read other places that the proportioning valve should be changed. I'm not really wanting to mess with that at this point too bad I'm just curious if anyone of you guys got that in depth with the swap.