I’m new to site. I know very little about Oldsmobiles. My buddy has a 1972 Cutlass Supreme, that he has decided to part out. He rebuilt his rear end and is willing to give it to me. I was looking to purchase a 1979 Cutlass supreme that has a bad rear end. Are the 72 Cutlass and 79 Cutlass rear in interchangeable?

 

As far as I know they are not.

 

Different widths, different angles on the control arm attach points. There are aftermarket arms with ball joint fittings that will allow you to bolt an early axle into the 78-88 cars without binding, but this still changes the suspension geometry. And of course it doesn't fix the 3" wider axle problem. By the time you buy custom wheels with the correct offset you might as well just get a correct axle for the application.

 

What are goals with the car? If you want a factory power cruiser, the 7.5" is adequate. If you want a HO 455, it will be on borrowed time, even if rebuilt with upgrades. That 72 rear is a nice stronger 8.5" Corporate geared rear with bolt in axles. Price out the conversion arms and offset rims and see if the cost is worthwhile.

 

Guys use to modify the 12 bolt chevy 1964-1972 to fit the G body chassis. There are companies that have conversion control arms for this project... BUt you will also need to move the spring perch ... deal with the over all width of the rear end and different offset rims will likely be needed. brakes are different... driveshaft will be to be cut.... Shall I continue?
lol.
The price of those control arms is not cheap. Then is the rear rebuilt and ready to run? If you are looking for a easy swap and low cost...Doubt this is for you. Take the rear sell it to a buick or olds guy and take that money and put it towards a good aftermarket rear end.
You should hurry as price keep going UP AND UP And UP Moser just jacked up all the prices on June 1st of this year so I am sure if things KEEP going it will happen again just before fall. GOD HELP US ALL.
We sell the Moser 12 bolt rears

Jim
JD Race