Pre 1980 differential in 1981 vette.
Safety Car
Joined: Nov 2008
Posts: 3,717
Likes: 551
From: Seattle Washington
If You Search this subject there should be a bunch of posts. The Iron Pumpkin will bolt to the Aluminum Batwing by leaving out 2 bolts. Then You need some of the 1/2 shaft and Strut Rod parts and the forward mount. Its all bolt in no fab.
Burning Brakes
Joined: May 2008
Posts: 1,116
Likes: 5
From: Middleburg Florida
Well, it's not completely a bolt in. The pinion mount is different. On the 80-82, the pinion mount is integrated into the differential. On the pre 80's it's not, it's a separate part. There may be some fabrication necessary to 1)get the pinion mount to fit at the cross memeber and 2) get the pinion yoke to clear the pinion mount bolt. You may also need to have a drive shaft made, the iron diffys are a bit shorter than the aluminium units.
You'll also have to buy new half shafts (the iron unit is narrower too) and then you'll need the flanges at the trailing arms vs. the yokes you have now. You'll need the strut rods for the eariler model differential, the good news here is that they mount under the unit putting the rods more parallel to the half shafts which is a good thing.
I know these things because I put a 71 iron unit in my 81....
You'll also have to buy new half shafts (the iron unit is narrower too) and then you'll need the flanges at the trailing arms vs. the yokes you have now. You'll need the strut rods for the eariler model differential, the good news here is that they mount under the unit putting the rods more parallel to the half shafts which is a good thing.
I know these things because I put a 71 iron unit in my 81....
