What years of IROC rear axle assemblies will swap onto a 1987 IROC. Drum or Disk and any
Gear Ratio.

 

Anything from 1982 to 1992 should bolt right up for sure, I think 1992 and up to a certain year will too, I had but sold a rear with disks out of a 1995, it looked just like the older models except for anti lock brake sensor.

 

The 4th gen rear is just a tad wider than our 3rd gens. But someone else did that 4th gen swap on this forum and worked fine.

-ws6formula-

------------------
1989 Pontiac Formula WS6
69,000 miles.
------------------------
305 TBI, 4.10 gears, SLP Zexel/Torsen Limited Slip Differential, 700r4 Corvette Servo, LT4 Hot Cam/Valvesprings, GM Aluminum Driveshaft, 2700 RPM Stall, Edelbrock Performer RPM intake manifold, Turbocity TB. Ran on 6-19-2001 again: UPDATED: 14.1 @ 97.68 mph. Dyno'd Bone Stock @ 172.6 rwhp, 266 ft-lbs. of rw-torque.

[This message has been edited by ws6formula89 (edited July 05, 2001).]

 

I've done a 4thgen rear swap with no problems. I put a set of 96 salad shooter rims on because the 98 axle is 1 1/2 - 2 inches wider than the 3rdgen axle. Plus had to get front adaptors from skulte for the 4thgen rims. The axle will bolt directly in. Just make sure you have 4thgen brakes for it.

 

'82-'84 had SAE brake lines, '85-up had metric. The only difference on a full axle is the wheel cylinders and lines, so swapping out the cylinders on an '82-'84 axle with metric type (like the '87) will then make it a bolt-in using your existing lines.

------------------
82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 w/'87 LB9 block, ZZ3 cam and intake, World 305 heads, Hooker headers & y-pipe, 3" Catco cat & 3" cat-back).
57 Bel Air, my 1st car. '66 396, 9.7 CR forged TRWs, Weiand Action+, Edelbrock 1901 Q-Jet, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 600 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).

 

Actually, only 82-83 axles have SAE brake lines.

The 84-current axles have the metric's. I put an '84 axle into my '86 and had no problems with improper brake line fittings.


------------------
-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

Thanks for the replies, I need info on the
87 to 89 if possible.