Time for adjustable proportioning valve?

[Dragstart]

Just got a new-to-me 1991 Supercab. It has a pulsing in the brakes, which I assumed was bad rotors. Took a look, and it just recently had a brake job done. Lines, rotors, calipers..........everything. Rotors are smooth surfaced, but still suspected they were warped from improper break-in.
I also had a drum in the rear that had a piece missing on the outer rim, so replaced that. Adjusted and bled, got good fluid when I bled it.
Afterwards, checked to see how the rears were working, and the answer was not too good. The left rear gets just warm to the touch and the right rear barely has any heat in it at all. You could fry an egg on the front rotors after the same test drive.
That sort of solved the why? of the new rotors getting warped. Previous owner just drove the truck not knowing about the bias problem and overheated the new rotors.
So, here's the question. Is this bias problem common, and is it time to install a manual proportioning valve? If any a of you have done it, what is a good valve to use and what problems and cautions are there with the install? TIA

 

[Dragstart]

Just got a new-to-me 1991 Supercab. It has a pulsing in the brakes, which I assumed was bad rotors. Took a look, and it just recently had a brake job done. Lines, rotors, calipers..........everything. Rotors are smooth surfaced, but still suspected they were warped from improper break-in.
I also had a drum in the rear that had a piece missing on the outer rim, so replaced that. Adjusted and bled, got good fluid when I bled it.
Afterwards, checked to see how the rears were working, and the answer was not too good. The left rear gets just warm to the touch and the right rear barely has any heat in it at all. You could fry an egg on the front rotors after the same test drive.
That sort of solved the why? of the new rotors getting warped. Previous owner just drove the truck not knowing about the bias problem and overheated the new rotors.
So, here's the question. Is this bias problem common, and is it time to install a manual proportioning valve? If any a of you have done it, what is a good valve to use and what problems and cautions are there with the install? TIA

BTW, new rotors are coming. NAPA is dumping their old line of rotors, part #PFR24885865. $25. There are some left in the system, they're scattered around, but you can have them ordered if you have a parts counter person willing to do it. That's the two WD rotor, but the picture on the website is wrong, it shows a 4WD.