Rear End Swap

[psquare75]

So I hear that a B-body rear axle (impala ss, etc) will fit the 73-77 body with no issues.

Anyone done this?
:confused:

[442MUCH]

So I hear that a B-body rear axle (impala ss, etc) will fit the 73-77 body with no issues.

Anyone done this?
:confused:

Not sure, but I the Pontiac LeMans, Buick Regal, Buick Century, Chevrolet Malibi and other A bodies should fit. Check it out first, call the local wreckers. They usually have a Hollander Exchange manual.

[psquare75]

Yah.. All have equally lame gears.

I've got a 3.08 sitting behind my garage, open diff... wanted something in the 3.4 - 3.7 range that would bolt in (I.E. Impala SS).

[ragz442]

I havn't done it myself, but heard of it done. You can get a posi rear end with disc brakes also, I believe they were installed in Caprice patrol cars. If you get a high mile used one your going to want to go through it anyway, might as while upgrade yours, unless you want the rear discs.

[damaged442]

I think Ron Fama ended up putting a Trans Am rear disc brake setup on one of his fleet. I can't remember which one off hand because he owns most of the 73-77s in the northeastern US. I think if anyone would know if it is possible, he would. I have no experience with this as I am proudly rocking the stock 2.41 and 2.73 opens in my girls. Ahh, it's great to have little old ladies in wheelchairs taking me off the line.

[PSU442]

I'm rolling stock too, bro. I always thought I had 2.56 (not sure where i picked that number up though.) What did the 77s come with? At least we get better gas mileage... right?

[damaged442]

If you check on the front of the right side of your rear axle (passenger side) there will be a code stamped. You may need steel wool or a wire brush, but it should be readable. If you can read the code and let me know, I can find what you have. Ironically enough, even with my gears as they are, my 442 only gets 8-10 mpg. I believe its a "quadrajet issue". I can pull up to 20 mpg with the 77 though.

[PSU442]

does your 77 have a 4-barrel?

[damaged442]

Yes, both cars have the 4 barrel.

[442MUCH]

I'm running a 3:42 posi unit with a W27 cover. I get about 235 miles to a tank at 60 mph.:( It only take's 5.89 seconds (with rubber in second gear) to get to 60 however.:D

I have a 1976 Corvette Stingray with the L82, 4 speed and 3:55 posi. The 442 would eat it for dinner.

[W451973]

The rearend will fit but NONE of them had any bigger then a 3:42 from the factory. AND you`ll have to deal with the 5 on 5 bolt pattern. Not to mention the Auburn carriors in them are JUNK. Do yourself a favor and buy a ring & pinion along with a carrior and have it put into your housing. Get a hold of Brian Trick ( 507olds ) on ROP. Or someone close to you to have one built.

[psquare75]

I'm most likely using the 3.08 I have kicking around from a 73 H/O, and I'll just do a powertrax insert. :cool:

[petrofyed]

alot of the cutlasses came stock with the 2:56 gears...at least according to the haynes manual i have for my car and apparently is what i have although after looking at the stamp on the axle it does not match the numbering configuration that it is supposed to, nor does it match anything else i have seen.....and my 455 (with a new q-jet on it) still only gets about 10 mpg

[PSU442]

i found this chart on zolav8's site (great site by the way):

http://v8cars.hu/cutlass/stuff.php?page=axles

i love how the bigger engines have the higher gears. They really didn't want the cars to go fast.... darn insurance companies. Talk about the dark ages.

[psquare75]

GM Still does that.. or did that in the 90's.

4cyl cavaliers got a 3.1x:1 ratio... v6 got a 2.78:1

[GT73]

Doubt a rear-end from a Caprice would fit into an 'A' body Olds, its a question of width.

Try looking for a GM 10 bolt posi rear-end from GM 'A' body cars such as a Monte Carlo, Grand Prix, Gran Am, Regal, Cutlass 'S', 442 from 73-77.

I installed a rear-end from a '74 Pontiac Gran Am (10 bolt posi with 8.5" carrier) with no problem into my '73 Cutlass Supreme.

Also, keep in mind that you cannot simply install posi gears into a non-posi rear-end. You need a 8.5" posi carrier (round part of the rear-end where the 10 bolt cover goes) as well.

Might as well get the entire rear-end with it too.

[zodiacblue442]

Standard ratio for 1977 (and 1976 if I remember right) is 2.41. Great for the Bonneville Salt Flats! :D If you get the first two letters of the code off the front side of the pass. axle tube, about 6" away from where the tube goes into the differential housing, that will be the code for the rear end ratio you have, assuming no one has changed the gears. Sounds like Bert can hook ya up with some code deciphering!


I'm rolling stock too, bro. I always thought I had 2.56 (not sure where i picked that number up though.) What did the 77s come with? At least we get better gas mileage... right?