Did Borg Warner make a rear end for a 1989 IROC?

I've found a donner car & the guy claims its made by Borg. I'll be taking a closer look in the morning so please get back soon.

What ratio's could it have?
Should it be posi being its in a IROC?
How can I tell by looking at the rerar end, is there a number to see on the case?

Thanks all,
CCar

 

Borg-Warner did make arear axles for 3rd gen cars until 1989. They are a strongerthen the normal 10-bols and have different internals and gear size 7 3/4 dia and can be identified by the nine bolts on the rear cover. All BW 9-bolts in IROC's came with a cone type Limited slip and the ratios are 2:77 & 3:27 for the 350 auto TPI and 3:45 for the 305 5sp TPI.1989 also came with the best rear brakes the 11.655 dia rotors and aluminum PBR calipers.
I swapped a 89 9-bolt onto my car. Picture of rear brakes


[IMG]local://upfiles/2696/2A288CF08D3A4CB78B3EE03AAA8A5825.jpg[/IMG]

 

This is a 9 bolt rear end, not a 10 bolt. He counted the bottom five bolts & assumed there werefive on top. However it does have the BW logo on the back right axle housing. I'm glad to here its a stronger rear but wish it had the 3:73 or 3:43gear set. I guess its easy enough to change. Can it be changed to a posi-trac instead of limited slip. I've also heard the 9 bolt is an Aussie manufactered rear end & that parts like seals & bearings are harder to find. I can't imagine bearings & seals being that tuff to come buy.

I have the car& now its time to start the work toswap all the parts I want over onto the 1990 RS. Like I posted before,,, the 89body isn't in that great of shape to restore but the 90 is. I'll try & post some pix's of both cars during the change over.

Any advice or short cuts you come up with would be appreciated.
CCar