i just picked up a ten bolt disc rear with the PBR brakes supposedly out of a 91 formula. when i went to look at it i didnt bring an offset 5/16 wrench and i couldnt get the bolt out to remove the axles and count the splines. but since it has the PBR calipers on it would this also make it an 28 spline axles rear?

also one caliper is missing the parking brake engagement lever that the cable hooks up to....where could i find that at? dealer is telling me its discontinued???

and is it worth putting another posi unit in this thing...supposedly has 100k on the rear w/ all original parts...it has 323 gears in it now and im thinkin ill just swap in the 373 gear and install kit and let it go til it blows up(hopefully after i sell it next year)

 

The word on the street is that all 91 and 92 rearends were the 28 spline axle versions

 

yes i know thats the word on the street 89 started the 28 spline axles...but im asking if a rear that has PBR disc brakes would also have 28 spline axles or when did the PBR brake option first come out

 

The PBR's came out in either 88 or 89, cant remember exactly. But I dont think they had any association with the types of axles or rearend. My 89 IROC has PBR's and its a 9bolt. I haven't personally gone through enough rearends to say for sure what year 10bolts came with 26 or 28 spline axles. But I do happen to have two pre 91-92 10bolts laying around, both of which are 26 spline, and the 10bolt in my 91 ia a 28 spline so I think its pretty close to accurate. Only way to know for sure is to check. If you do have the 28 spline axles you could always consider a 4th gen posi unit. SLP used to sell these with 0 miles for $99 so it was a deal, but nowadays best bet to find the cheap deals is to find used. I picked up a relatively low mile '00 SS rearend for cheap and I'm gonna use the posi and rear LS1 discs to upgrade the stock 10bolt w/ drum in my 91 Z28.