I have a 1985 IROC Z with 4 wheel disc... Was this the stock rear end or was it swapped? On my rpo it says I have the Posi Limited slip...

 

yes it is or could of came in the car, if it's a 10 bolt disk rear. i believe the 9 bolt didn't start untill the 350s were put in the irocs.

 

383,

The discs on all the corners was probably a stock item. If your RPO tag shows the "J65" code, it had four-wheel discs from the factory.

If you want to see what else you might have, check this file:

RPO Codes.pdf


Ede,

Another reason the '86 was the "bastard-child" of the breed. You could get the Borg 9-bolt, but only a 305... &

 

What year? Rear discs were available in F-bodies starting in 1979.

Rear discs were available on your car. It probably doesnt have the Borg-Warner rear though, I think they only used those on Birds before 87.

Hey Vader, the BORG was available 85 too. My TA had it along with the discs.

 

AFAIK, rear discs were available on all thirdgens. For secondgens, the TA had them available before the Z, but I can't remember the exact dates.

 

The 1969 Z-28 had an optional rear disc set-up available. Production #s were low.

I found one in the late '70s for $75 and sold it to a restorer for $150.

I thought I made a good deal. At the time. Should have kept it.

jms

 

Really? Never knew that.

Somehow, I think that $150 was a gift.

 

4WD first came out in the 79' T/a's and formulas in the WS6 package, 150$ for a disc rear from a 2nd gen is a giveaway, every 2nd gen builder wants one forsure, there fairly hard to find, and ONLY on the firebirds, no camamo option untill the 80's

 

Refering to the 1969 Camaro SS options---Quote-"...An SS Camaro equipped with seven-inch Rally Wheels (part of power front disc brake equipment), spoiler and cowl induction hood looked like a Z-28. About two hundred Camaros, all Z-28s, had four wheel disc brakes this year." ---from Chevy Super Sports 1961-1976 by Terry V. Boyce, copyright 1981, page 155, about half way down the page in the middle of a paragraph.

This was the very first book I looked in, for support of my above position that 1969 Camaro Z-28s were available with 4-wheel disc brakes.

I have about 3,000 magazines and books I could continue to search through. I've kept all I bought since the late 1960s. Could probably find SEVERAL more references in a couple of hours.

Just jump over to CamaroZ28.com and ask on the 1st and 2nd gen board.

The disc-brake rear end I referenced in my earlier post came out of a VERY trashed '69 Z-28. Very RUSTY and pure JUNK. Now-a-days, it would be restored, but in the late 1970s, it was just a junky old car.

A side note---in the late 1970s, the Cadillac Seville (the one that looked similar to the same year 4-door Nova), was available with a disc-brake rear end. If I remember correctly, the Seville was available with the disc rear a year or two before the T/As.

That Seville was based on the Nova, which was on a chassis that was almost identical to the 2nd-gen F-body. Not quite a true bolt-in but the Seville disc-brake rear can be put into a 2nd-gen F-body.

jms

 

Yea, I think the Seville came out in 75, and the rear discs were available in 76 or 77. The early thirdgen rear disc calipers are the same junk used on the Sevilles. Ford was doing it too, they started using rear discs in I think 75. Was even available on the lowly Granada.