hey guys just put in posi rear disc in my 87 camaro from an 83 z28 and i was wondering if it was worth to put newer pbr from a later model disc camaro and an estimate of how much to do it?

 

i spend $600+ doing mine. but that is for a 9bolt and includes the cost of the rear end, NEW calipers/rotors/lines/backingplates/pads and a willwood proportioning valve.

one thing to keep in mind is that the 89+ PBR disc (sometimes called "1LE" ) brakes use the same proportioning valve as a drum car. SO if you just converted to disc, and changed your combo valve, you are going to have to change it back. OR you can do what i am doing and go with an adjustable one from summit (40$ + about 10 fittings) and have ultimate control over how your braking system acts.

if you have a 10 bolt you are in luck as the backing plates required for this swap are still sold new by GM. if you are doing the swap on a 9bolt you are not quite in as nice a shape. GM no longer makes them as they were a one year only item (1989 last year for 9 bolt 1st year for PBR). HOWEVER you can modify the backing plates with a new bolt pattern to fit your 9bolt, or order them professionaly modified from Ed Miller (ebmiller88 on Tthis site IIRC). that is the route i went. in fact i ordered my entire kit from Ed. great quality all around.

if you would like to see what others have done there are many threads out there. a search would yeald a few good ones. i happen to have what i feel is the best one bookmarked. you can find it HERE:https://www.thirdgen.org/forums/show...hreadid=249098

good luck with your swap.

 

I just put a 89 9 bolt rear in my 92 z28 and I tried to put the proportional valve from the 89 onto my 92 and the lower back brake line was a different thread and I stripped the prop valve. I went to the local chevy dealership and his book showed a different prop valve for 91-92 with rear disc than 90 and older with rear disc and also the 91-92 cars had a different prop valve for rear disc vs rear drum. I just received the 91-92 rear disc prop valve and it has a bracket made onto it that bolts to the master cylinder. The 89 rear disc valve does not have that.

 

89 was a transition year, there were two different thread sizes used. To match the lines on your 88 you would have needed the "late" 89 part, instead of the "early" 89 part.

All the valves I've bought though came with the bracket to mount to the M/C though.

 

So I just converted my 88 Rear Drums to a 91Z PBR Rear. Are you saying that the prop valve is the same between the 2?

 

Have the local chevy parts guy look up one for an 88 and take the part number and buy it from gmpartsdirect.com I saved about $30.00. They made several prop valves and I learned the hard way by ruining one.

 

Prop valves (combo valves) are different for disc and drums, and differnt years.

Ed

 

I have the original prop valve that was in the car with the rearend that I bought. Its in good shape, looks just like the one in my car already.

 

They are different internally, they will all look the same on the outside.

Ed