Firebird rear

[gonein67bird]

So I have a 67 firebird with a 8.2 non posi and a 2 speed auto stock. I have changed the 2 speed to a 200r4. I just got a 8.5 posi from ebay not exactly sure what it is out of, I installed it this weekend.I swapped over all my brake parts they fit fine, had to change the u-joint no big deal. It is definatly narrower than my 8.2 by at least an inch. Does this sound correct? The drive shaft seems to be O.K. but I have heard some people say you have to shorten it. Is this true with all?

[big gear head]

It's probably a Nova 8.5. It will be 60 inches wide overall. If it uses the 3R u joint then it will be a '76 or later. You can find out what it is by the code stamped on the right axle tube.

[gonein67bird]

So I found out it is a 72 nova rear. I guess thats why they called them wide track pontiac. so do you usually have to shorten the driveline with this swap?

[rohrt]

It was my understanding that the driveshaft needs to be shortened by 1 inch when changing from an 8.2 to a 8.5.

[68Formula]

I've heard rumors that the width of the 8.2 is wider on the Pontiac. I haven't had the wheels off to confirm.

I do have a 72 Nova 8.5" as well, but with LT1 brakes. It measures 60" flange to flange.
Wonder if the difference could be drum vs. disc? Is your Nova rear with disc brakes or drums?

[big gear head]

The '72 to '75 Nova rear ends have the 1310 yoke and usually don't require the drive shaft to be shortened. The '76 and later Nova rear ends have the 3R yoke and usually require the drive shaft to be shortened about 1 inch.

[gonein67bird]

The nova was a drum brake rear and my pontiac was a drum brake rear. It is 1" narrower

[zman1969]

did you buy it from me? yes on the nova housing and the 67-69 birds were wider by 1" they were same as second gens -different perches. and Big gear head:
"The '76 and later Nova rear ends have the 3R yoke and usually require the drive shaft to be shortened about 1 inch."
I have build dozens of nova rear ends and the all have the same smaller joint yokes??

[T_Raven]

It's probably a Nova 8.5. It will be 60 inches wide overall. If it uses the 3R u joint then it will be a '76 or later. You can find out what it is by the code stamped on the right axle tube.

Do the '75 and later axles bolt in to a first gen F-body? I thought it was the 68-74 had the same perches as the 1st gens and the 75+ had the same as a 2nd gen F-body.

[zman1969]

Do the '75 and later axles bolt in to a first gen F-body? I thought it was the 68-74 had the same perches as the 1st gens and the 75+ had the same as a 2nd gen F-body.

68-78 nova's or x-bodys or GM equivalent and cad Sevilles used the same rear-same perches and width BUT the 75-78 8 cyl had 8.5 the 6 cyl had the 7.5 rears. The Sevilles in 76 had drum brakes but were bigger than the normal 9.5" drums - more like 11". The 77 and later had disc brakes similar to the 79-81 trans ams but they also had a 5x5 bolt pattern instead of the 5x4 3/4 as most of the smaller GMs. All these housings-except the 7.5 are pretty much the same if your 8.2 chevy rear has good axles they will fit in the 8.5 rears as they are 28 spline also. the pontiac axles are bolt in and have the press on bearings and wont work. Also the first gen firebirds are 1" wider than Camaro or the Novas as mentioned above.

[gonein67bird]

Another question. My old rear had the 2 "traction bars" built on to it. Was this just a Pontiac thing or did some Chevy's have this? My understanding was that 326 and 350's had 1 and the 400's had 2.I never had any wheel hop with the Pontiac rear should I weld these onto the new Nova rear?

[big gear head]

The '67 to '69 Firebird used the same rear end that was in the Tempest, Le Mans and GTO. If you look at one you will see that the eyes for the upper controll arms are cast into the center. The only difference is the spring perches or lower controll arm brackets. If it went into a Firebird then it got the spring perches, if it went into a Tempest, Le Mans or GTO then it got the lower controll arm brackets.

[gonein67bird]

http://cgi.ebay.com/ebaymotors/RARE-...Q5fAccessories
no no, traction bar like this. this one has 1 but mine has 2. with the nova rear I have some wheel hop now.should i use these or get new springs? or both?

[big gear head]

Competition Engineering makes a very good J bolt traction bar and the Cal-Trax bars are also very good.

[zman1969]

Another question. My old rear had the 2 "traction bars" built on to it. Was this just a Pontiac thing or did some Chevy's have this? My understanding was that 326 and 350's had 1 and the 400's had 2.I never had any wheel hop with the Pontiac rear should I weld these onto the new Nova rear?

Pontiac had singles and duals -even dual traction bars on the OHC 6 -go figure the bar on the Firebirds were cast iron -Chevys used a different single only square-round bar depending on 350 or 396 you can swap them over to the chevy rear - Im pretty sure most or all of this was 67 only, neither of my 69 birds had em and none of the 69 camaros I've owned them had them either

[gonein67bird]

67 only must be the mono leaf springs and the non staggered shocks. I think I will swap them over.

[68Formula]

Gone,

Did you end up having to modify the driveshaft?

I have a '72 Nova rear as well to replace my original Pontiac 8.2" on my '68.

I've been delaying doing the rear swap because I haven't decided which trans I'm going to go with (didn't want to do the driveshaft twice).

If I don't have to modify the shaft, I'm just going to do the swap now.

Also, does that mean I use the yoke on my current driveshaft?

Thanks.