SSnthe10s

i was just wondering i might be getting a parts car and i would like disc breaks. and did these come with the 9bolt by any chance?

thanks

stevem

no they did not,i belive it has to have the borg warner(9 bolt) rear end to have discs.

hairbear

No, like the guy above said except 10bolts could also have had "disc brakes".
Heck IROCs had some many combos back then. You could have got 305s,350s,TPI,4bbl,non posi,posi,5-speed,auto,steel hoods,plastic hoods,etc.

SSnthe10s

this one had a tpi 305 with a 700r4. im praying its a 9bolt.

87DJP2001

No, not all IROC-Z had disc brakes. What you may get is a 10-bolt 2:73 rear with drum brakes.
This was the common set up for a 305 TPI and the 700R4 Auto. All 9-bolts with Disc came on 350 cars (J65) and 305 TPI's with Manuals & (G92) options.

RedIrocZ-28

What year man? Mine is an 89 and it did have a 9 bolt and Disc brakes. DJCobols car is an 89 and had a 10 bolt and Drum brakes. '89 is the most likely to have a 9 bolt and discs

87DJP2001

What engine do you have in your car??? (also what is "it did have")??
And nothing is more wrong then "89 is the most likely to have a 9-bolt and discs".
The 9-bolt came only in 350 cars with the
2:77 std & 3:27 with G92 option and 305 TPI Manual cars came with a 3:45 G92 option. Disc brakes RPO J65 was also a option but required on 350 and G92 cars.

So your statement is wrong and incorrect. Do some reseach for facts and not what is "likely".

stanghunter211

Count the bolts on the diff cover, it couldn't be simpler. But depending on year, a 9 bolt doesn't guarantee you "good" disc brakes. If you get an early 9 bolt, say 86-88, they still had the cast moraine calipers. 89-90 was the good stuff, 91-92 went back to the 10 bolt, but retained the PBR aluminum calipers.

Will

METHOD_MAN

first off the 9 bolt aussie rear end is junk....and an 89 is most likelyyyyy???? what? what do you mean most likely....and stang hunter how do you figure that the 9 bolt rear discs in 88-90 are better than the 10 bolt disc in 91-92?

stanghunter211

9 bolts are stronger than 10 bolts. This has been discussed hundreds of times

SSnthe10s

jeez where are u getting your info

87DJP2001

Before and up to 1988 both 9 & 10 bolt rears had the 10.5 rotors and iron calipers. In 1989 the 9-bolt had the 11.655 rotors and Aluminum PBR calipers, the 10-bolt had no changes. Now 1990/92 with the 9-bolt discontinued the 10-bolt now had the same 11.655 rotors and PBR calipers.