My 48 Olds had the master underneath when I got it.Put residual valves on it(Wilwood,junked the factory piece) and worked fine.Got tired of having to lift the hatch in the floorboard to check the fluid so I put it on the firewall.Being the master IS higher I figured,like you,that I wouldn't need the residual valves anymore.WRONG.Never could get a really good pedal.Decent but not great.Read somewhere that the seals on the wheel cylinders require the constant pressure that a residual provides to keep enough pressure on them to keep from leaking.Now,I don't know if that is true or not,but I do know that when I put them (res. valves)back on that the pedal instantly improved :shock: Don't know if I just got lucky or not,but was a definite improvement.Hope you get it figured out and let us know what happens.BTW,can I have your grill??The Chevy's were 10 times nicer looking than the plain ol' Olds'.