1972 Fury III, and 9 1/4 rearend

[MN72Fury]

I have just purchased a clean 1972 Fury III, I plan to replace the 360 motor with a 440 and today I found a 9 1/4 rearend with slip lock and 3.23 gear and disc brakes off an Imperial

3507891, it was on a 1971 Charger (not orginal on car).

It is 47.30" between leaf springs

I presently have a 8 3/4 with 2.71 open gears

Is the 9 1/4 going to fit properly on my 1972 Fury?
Is there any need to change yoke or any other part?
Is 3.23 enough to launch a C body.

I purchased the rearend and hope it works, it fits should I put in "green seals" or do anything before installing.

 

[detmatt]

Welcome to the site from the Motor City! Post up some pics of your new Fury.
I think that axle should bolt up and I think you're thinking about Green bearings, not seals. Some like the Green bearings and some don't. I would go with OEM style.

 

[polara66hardtop]

I would measure the width between the drums between both. The C body is a wider car, I believe perches are further apart. Better to measure once.

 

[commando1]

If it is a 9-1/4 and it is from an Imperial, it must be from 74-75. If that's the case you have a rather nasty problem on your hands with the disc brakes that come with that rear.

 

[polara66hardtop]

Sorry, I didn't read all the way through, seeing 47.30 is the B body width. I believe a C body is 52 or so between drums. Commando1 is correct about the disc brake issue.

 

[MN72Fury]

If it is a 9-1/4 and it is from an Imperial, it must be from 74-75. If that's the case you have a rather nasty problem on your hands with the disc brakes that come with that rear.

I have a 489 case rearend in the car now. The same car with the 360 motor (I am having it painted now)

I see some here don't like the green I do. This is a green beast I drove from Alabama to Minnesota. It ran well during the trip, but the rear gas tank seal leaked, the radio didn't work and it barely had enough power for some hills. The speedo cable went out and began screaming at mile 800 of 1300. Anyways the car made it to Minnesota - but I realized I need MORE power and acceleration. As all large Chrysler it floats and I plan to improve the suspension in the near future. Still it was really fun to drive on the road trip.

I wanted a car without a lot of rust, there is a 440 fury on ebay that is barely there. I really do want a 440 with upgraded rearend and suspension to drive over next decade. This car was rust free

You are right the rearend was from a 74-75 and then put in the Charger. It has new calipers and rotors were turned so I was not worried about the brakes so I bought it today. I can contact the Ram Man for new brakes will the rearend work? What is best gears 3.23 v 3.55.

THANK EVERYONE FOR THEIR HELP - GLAD TO SEE SO MANY APPRECIATE THE LARGE FUSELAGE C BODIES

 

[MN72Fury]

It is a 489 case on the present rearend with an open 2.71

The motor is a 360 2 barrel

Goal would be a 440 with 450-475 hp and a suregrip rearend -

I am not sure if the 9 1/4 is worth messing with - assuming I put new brakes on it

 

[65sporty]

The 8 3/4 that's in the car is OK you may want to change the ratio though, the 9 1/4 would be good also it has been used in later trucks and seems fairly stout

 

[Mr C]

A 9 1'4 is a great Diff. 3.23 is an ideal ratio to launch a C body and retain highway driveability.

 

[MN72Fury]

Brake issue with Imperial 1974-75

Please let me know the problem with the brakes

I know the parking brake did not work on the 9 1/4 Rearend I purchased.

Is there a brake system you recommend?

 

[polara66hardtop]

9 1/4 is a great rear end, but why change it. the 8 3/4 is a tough rear end, and it is easy to change ratios. The 9 1/4 Isn't. All I see is more work.

 

[65Fury440]

You would be way farther ahead to keep the 8 3/4. Here is another chart for reference, it doesn't cover 74 up Imps though. You could probably sell that 9 1/4 and get a 8 3/4 third member. You have a really cool car, welcome to the club!
http://www.bigblockmopar.nl/tech/mopar-rearaxle-dimensions/

 

[Mr C]

If you decide to keep the 8.75, I'm willing to discuss the purchase of your Imperial rear rotors if they're within spec.

 

[70bigblockdodge]

Sell the 9 1/4 to a restorer those brakes will be difficult to service on a driver type car. Use the money to have someone change the gears and put a sure grip in it or learn how to do it yourself then you will have 2 things, more money and a new skill.

 

[twostick]

Please let me know the problem with the brakes

I know the parking brake did not work on the 9 1/4 Rearend I purchased.

Is there a brake system you recommend?

The problem with the Imperial disc brakes is the parts are made from unobtanium.

The 8.75 will do just fine. Either find another case with the ratio you want ie 3.23's or build your case. Steer clear of the Auburn or cone type Sure Grip unless it is free. They are mostly worn out if you find a used one and they can't be rebuilt without some machine work that is beyond most shops. You want a clutch type. Easy to rebuild and they fit all case types by using the bearings that go with the case.

741, 742 and 489 will all fit your housing. Don't let anyone tell you the 741 gear is "weak". The pinion shaft is bigger than the 9" Ford. Because a lot of people think it is an inferior diff, you can usually get them a little cheaper.

Dr Diff is the go to guy for all your axle and brake needs.

http://www.doctordiff.com/

If you just have to have 4 wheel discs, he has kits that will fit your axle.

IMHO for the average build, the 11" drums properly built and setup are more than capable of using up all the traction the rear tires can provide.

Kevin