[fauXGT]

If your rear is drum, the factory proportioning valve is said to be different than on discs. Most places will say you need an additional adjustable proportional just on the rear line. I didn't do that, and the 1st time I slammed on the brakes it didn't nose dive like most. But I have converted the front and rears from the GM 98-02 Camaro and still have the aftermarket mechanical anti-lock modules.
I can't remember the mech anti-lock company, being that was over 30 years ago, but they are the gold barrels on the master cylinder. One for front and one for rear.