Third Generation (1982-1992) have a diff that measures 62" between wheel mounting surface to wheel mounting surface. That makes them physically great for dropping into the AD. I've used both the posi/disc diffs from an 89 IROC-Z and a drum diff from an 88 in my 54 truck. These diffs have the 5 lug on 4-3/4" lug pattern and the most common R&P ratios are the 3.08's, 3.42's and the more illusive 3.73.
As for the e-brake hookup.....the stock Camaro full length cables can be adapted to the stock AD emergency brake system using cable clamps. The Camaro swaybar was also a perfect fit for the AD truck. The bar was simply moved from the bottom of the diff on the Camaro and mounted to the top, using the stock Camaro hardware. The installation requires only one hole on each side of the frame to connect the control links. I have some pics in my Webshots albums of the modifications.
Be advised that the Camaros used coil springs so you'll need to either torch off the coil mounting hardware or tough it out with a cut-off tool or even a grinder. The axle tubes on the Camaro diff are 2-5/8" diameter so you'll want to put a strap of flat band stock under your 3" U-bolts. I used 1-3/4 trailer spring perches from Tractor supply as well as their bottom plates. Welded on a large bolt to that plate for my lower shock mount.Do not heat up the U-bolts and try to reduce them down to 2-5/8". They may/will break!
In addition, you need to realize that switching to the 5 on 4-3/4" pattern will limit the number of salvage yard rims available. However, if you use the same pattern disc brake upgrade on the front, there are numerous new rims with 3-1/2" backspacing available in 15X7 and 15X8 that will give you good tire/wheel well spacing. I'm running 235/70/15's on 15X7 rims on the front and 275/70/15's on the rear. The front tires clear the stock and also upgraded tie rod ends by 5/8-3/4". If I had it to do again I would use 235/70's all the way around so I could rotate the tires.
On choosing discs or drums: I've used both and prefer the drums. My setup is not boosted and I found that even with an adjustable proportioning valve, the rear disc brakes had a tendency to lock up on wet pavement. Additionally, the IROC-Z disc/posi diffs have an axle seal that is difficult, if not impossible to find. The emergency brake internal ratchet system is also troublesome. I would suggest the drums.....they work fine when combined with the front disc upgrade.
Granted it will take some work to clean off the coil spring hardware but the availability of both the 3.08 and 3.42 units (from behind 2.8L V6's), lower mileage than some of the 50-60's diffs, and the $100-150. price tags make them a viable option.
Hope this helps.
Dave
