Moving in the opposite direction here, but I got a great deal on a rebuilt 9" that was previously installed on a thirdgen so it has the proper steel and e-brake lines for a direct bolt in. My car came factory with PBR disc brakes. The plan is to eventually buy a big Ford 9" disc conversion but for now, how will the rear brakes react to a factory disc/disc proportioning valve? Any experience? I tried searching but not coming up with what I'm looking for. Trying to decide if it's necessary to change the prop. valve or install an inline adjustable prop. valve.

 

I'm sure others can argue against me here, but I've had an lsx rear in my car with dual piston calipers in it, back to a drum brake 10 bolt, to a 9 bolt with lt1 disc brakes, and I've never changed the proportioning valve.....got to a point where I was breaking so many 10 bolts that I just tossed whatever junkyard rear I could find in it to keep it on the road. Never had an issue.....put it in and see how it stops, you probably won't have a problem, especially if it's temporary and it gets ya on the road for hot rod season

 

Sounds good to me!