Hello, any help is greatly appreciated! Here's the deal. I have a 91 350 375 hp, stage 2 700 r4 and a Borg Warner 9bolt 3.27 posi iron disk breaks.
Basically I need to know what Prop valve I need. Seeing as I have no rear breaks. It was a drum rear end.
Also, what bracket I need to upgrade to 4th gen breaks? N if I upgrade to 4th gen rear breaks then which prop valve do I use??
Where do I find a rebuild kit for the POSI UNIT???
What's the best aftermarket ring n pinion???
How much hp will the stock axles take???
Rear installation kit????
Any info is appreciated!!!

"the little red guy on my shoulder says........FASTER!!!"

 

Wow.. Lotta ???s. No biggie. I will answer a few for u.
When u say 4th gen brakes, u r referring to ls1 brakes,.right? I recommend either flynbye.com or bigbrakeupgrade.com to do a conversion.
As for a prop valve. I've heard of people.just getting one from a car that came wit disks.
That rear is plenty strong for your 375 horsey motor. I don't know if they have rebuild kits, but look into 9bolt.com for other 9 bolt needs. Hope this helps.

 

With the Delco-Moraine set-up, the standard combination valve would be ideal (found on metric valves from around 84-88); however, the tube nut threads on those years won't fit your 91.

The site below sells the correct 9-bolt backing plates, which would allow you to run 89-97 PBR's. You'd need the second design 1LE valve, which would fit your 91. The site also sells the correct parking brake cables:

http://www.flynbye.com/

JamesC

 

For rebuild parts for the 9 bolt do a search in the transmission/drive-train section for "cheap 9 bolt borg warner parts" or something like that. I just put that thread together maybe 1-2 weeks ago.

 

Also, what bracket I need to upgrade to 4th gen breaks? N if I upgrade to 4th gen rear breaks then which prop valve do I use??

4th gen rear brakes or front brakes? Rear brakes from 89-97 are roughly the same. the 89-92 ones look a little cooler, but are the same basic design as the 93-97. The 98-02 brakes require a bit more work to get the e-brake to work, no off the shelf backing plates available for it. Honestly I'd just use the factory drum brake prop valve. The disc brake valves barely give the rears any pressure at all, the drums apply MORE pressure if I remember correctly, If you can find a safe place to experiment, check and see whether the front or rear brakes lock first. If the front brakes lock, you're good. if the rear brakes lock, be careful not to slide into anything and swap for a 90-92 disc brake prop valve.

Where do I find a rebuild kit for the POSI UNIT???

Look up "9 bolt posi cones" on the search. cones are available, they require a little machine work on the carrier, but if the cones have worn down too much the carrier may be beyond repair.

https://www.thirdgen.org/forums/tran...urces-9-a.html

What's the best aftermarket ring n pinion???

Take what you can find. I like my Yukon gears... they work.

How much hp will the stock axles take???

You can blow em up with the stock power number if you're unlucky. You can make em live deep into the 400-500hp range if you're lucky. They're tougher than 10-bolts, but they're definitely not indestructible.

Rear installation kit????

Do you mean for gears? If so... ratechmfg.com Do you mean to install the whole thing into the car? Just use what you have.