The only cars in 1980 that have a 9" rear axle are Ford Granada, Mercury Monarch and Lincoln Versailles. 1980 was the last year for the 9" in cars.

1980 Granada/Monarch were also available with the 7.5" integral rear axle and the 8" rear axle that looks like a 9." All 1977/80 Versailles' have a 9" with rear disc brakes and 5 lug wheels on a 4.50" bolt circle.

LTD/Grand Marquis were downsized in 1979, Lincoln Town Car was downsized in 1980. 1980/81 Lincoln Town Cars have a 8.5" integral rear axle, 5 lug wheels on a 4.50" bolt circle.

 

The Granada/Monarchs could have one of four different rear ends; Ford 8-inch drum brake rear end, drum brake 8.7" integral rear end, 9-inch drum brake small axle bearing rear end or a 9-inch disc brake large axle bearing rear end --this last one being the same disc brake rear end that was put into the the Lincoln Versailles as standard equipment.

The drum brake and disc brake 9-inch rear ends in the Granadas/Monarchs and the disc brake 9-inch rears in the Versailles only had four possible factory ratios in them; 2.47, 2.50, 2.75 or 3.00:1 -- great for gas mileage or highway cruising but, not so good for towing/hauling. These two 9-inch rear ends could have an open differential, an optional 2-pinion Traction-Lok differential or an optional 4-pinion Traction-Lok differential. But, these 9-inch rear ends are too narrow for use under a Bumpside truck.

This is a small axle bearing 9-inch drum brake rear end I have from a Mercury Monarch.



This is the same Monarch drum brake 9-inch rear end from the photo above, after I adapted '94-'04 Cobra Mustang rear discs to it with adapter brackets I designed. --this was for installation under my '68 Mustang.





However, and again, if a person is wanting to swap a 9-inch rear end with a 5 x 4.5" lug pattern under a Bumpside, the '80-'83 F100 9-inch with the 5 x 4.5" lug pattern would be the best way to go to accomplish this.

 

Wouldn't it be easier to just buy new 4.5" 28 or 31 spline axle shafts from Currie's, Moser, etc for a 67-72 housing than to try and find an 80-83 F-100 axle, and then change the spring pads to the 67-72 width? Sometimes it is better to apply the time vs. money principle. Especially for people who have no good JY's around their area with everything getting crushed and shredded to go to China.

 

Found what I was looking for. Scroll down a ways and it describes swapping Torino ect driverside axles into F100 9 inch

1948 through 1960 Ford F-1 and F-100 Rear Axle (differential) Swaps - Ford-Trucks.com

 

There are a number of different approaches that can be taken to modify/swap parts to accomplish what the OP is after --although the question of why the lug pattern is being changed still remains to be answered.

If it's for the reason that a CV front suspension was installed, merely changing the (28-spline) axles out in the existing Bumpside rear end is still going to leave you with a narrower track width than the front --if looks matter and you're wanting the rear wheels/tires to follow in the same track as the front. The wider track width of a Bullnose (or Dentside) 9-inch rear would also give some degree of better ride stability than the narrower Bumpside rear end.

The '80-'83 5 x 4.5" lug 9-inch rear end will also come standard with stronger 31-spline axles (approximately a 30% increase in strength over the 28-spline axles).

I'm fairly certain the 5 x 4.5" lug '80-'83 9-inch rear end comes with the 'Torino' style large axle bearing flanges. If this is the case, this rear end housing lends itself to the ability to bolt on later model rear discs from a '94-'04 Cobra, '95-'01 Explorer or a set of Ford Racing rear disc brakes that are available. About the only rear discs that can be adapted to the Bumpside old style large bearing rear ends are the disc brake calipers from a Chevrolet with a mixture of various parts to install them.

Having the '80-'83 F100 5 x 4.5" lug 9-inch would give a person the foundation to greatly improve the end result of incremental improvements on it, compared to what you'd be able to do with the Bumpside 9-inch in final fit, appearance and functionality.

Presently, there are about 50 listings at Car-Part.com for the '80-'83 F100 5 x 4.5" lug 9-inch rear ends so, if you couldn't find one locally, they are available through the various wrecking yards listed on there.

 

If you just want to change bolt pattern, have the axles redrilled to new pattern. The last set I had done cost about 65.00 and some shipping

 

I think I would rather swap the axles than reweld the spring pads on the 80-83 rear. Plus I want to run 10 inch wide wheels in the back. That works better with the narrower early rear end. But, if I were going to run 8 inch wide wheels the 80-83 rear end becomes an option for me.

 

Looks like you are correct Steve. Here is the listing for the axle bearing retainer gaskets for Bullnoses. Between the 4020 bearing retainer (holds the axle in) and the 4010 axle housing.
80/83 F100 with 2800# axle....D3OZ1001A. 3 3/16" I.D. In the 70's OZ was Torino. Until replaced by the LTD II in 1977.
80and newer Bullnose F100/150 with 3750# axle....D8AZ1001A. 3 11/64" I.D. And AZ meant Full size Car.


Here are the 73/76 Torino axle bearing retainer bracket listings. Compare to the 4020 truck listing in Bill's post above.


1976 Torino with large wheel bearing.....D3AZ4020A.
73/76 Torino (and 77/79 T-Bird) with large wheel bearings......D3OZ4020A.
74/76 Torino (and 77/79 T-Bird) with tapered roller wheel bearings....D4OZ4020B.

 

Last chance 53, where did you get your axle's redrilled?

 

I don't know for sure, but it seems to me a local machine shop to you ought to be able to do most if not all of it. They should be able to create a plug to plug up that 6th big hole that's for accessing the wheel bearing retainer nuts. Someone else may have to weld it in. Then the machine shop should be able to drill the 5 stud holes. And enlarge one of the original stud holes to become the new 6th big hole.

 

I had the axles done buy moser engineering

 

$65 seems very reasonable I think.