I have a 1979 with a stroker 347 roller motor. It is just not as much fun going to the track as it used to be and I am starting to put it back into cruiser shape. I had converted it to manual brakes but want to go back to vac assist. I had also did a rear dis conversion. Do I need to add a proportioning valve since it was originally rear drum? Iam pulling the tunnel ram and going back to this look. I have a wider set of tires that look better too.