9" ford

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kittypancake

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I want to change my 7 1/4" rear, but all the 8 3/4' rears have appearantly been gold plated! Now I have a 9" ford in my back yard thats about 1 1/2" narrower than the 7 1/4. What kinda can-o-worms amI gonna open trying to adapt this? The bolt pattern is bigger. Change the axels? I guess i'll need to move spring mounts. what about adapting yoke to driveshaft? What am i not thinking of? Maybe someone could just direct me to a silver plated 8 3/4.
 
If you sure the Ford is that close, the spring perches may be close, too.

So far as adapting the joint, there SHOULD be a so called "conversion" joint, and if not, any decent driveline shop should be able to adapt a Ferd end to yer Mopar shaft
 
Not sure on the yoke to axle centerline on the 9" compared to your 7-1/4. It may be the same (or real close) or it may be different. If it is different you may have to get a shorter or longer driveshaft depending on which way it is off. As for the axles it depends on how you want to go about it. If the Ford rearend is out of a car it most likely has the large (5 on 4-1/2") Ford/Mopar bolt pattern that was used on B, C, D, and E bodies. You can change your fronts over to the big bolt pattern also which opens up a world of fitting wheels. If you don't choose to do that there is 2 other ways to remedy it. Have the axles and drums drilled to the small Mopar bolt pattern if there's enough meat to them or you can give Moser's a call and have them build you a set of axles with the small bolt pattern. But be ready to dig deep in your wallet if you choose that route.

One other thing you may run into is the 7-1/4 axle tubes are only 2-1/2" diameter. Generally everything else has 3" tubes. With that in mind your U-bolts and shock mounts won't work so you'll need a set of them from a 8-1/4" or 8-3/4 rearend.
 
Bolt pattern Should not be a big issue since Mopar has a 5 on 4 1/4 like ford does you must have the small 5 on 4" TIME TO UPGRADE ANYWAY...lol.

Spring perches again NOT a big deal. Cut and paste...lol. :)

Only think you need to watch for is the backspacing of the wheel if thr new rear is narrower. But if your getting new rears to macth the bolt pattern then you can solve that with the purchase OR run a spacer and if needed some little bit longer studs.

Conversion u-joint as mentioned any Auto parts store should have that.

Done.

Only problem now is you have the bad luck FORD product in your Mopar....lol. :) JIm
 
How much were you looking to spend for a 8 3/4 ABody rear?

Let me know cause we build the housings and can get you axles and OF COURSE build you the center too. Jim
 
Well, when I called my semi-local wrecking yard, they said, "$500-$600 if we can find one." They haven't called back yet.

I guesstimated 1k - 1200 total. but then i got edumacated!
 
Well when was the last time a A-body 8 3/4 was produced? lol. They just are not around in stock form and the ones that are are under cars. We can make the housings from other wider Mopar housings BUT that will have some labor involved too.

500-600 for a full working rear is not out of line for todays pricing.

How much money do you have in a motor? Trans?

DAys of 200.00 rears that actually run are well past. Besides that 20 year ago the rears were also 20 years younger and 20 years less miles too. NOW they are over 40+ years old and will need rebuilding etc.

Watch the used parts out there... Do your home work and spendf money on the parts that will bring you the best bang for your buck and longevity...EVEN if you have to wait another year to save up the money for good/ New parts and service.

Jim
 
Well when was the last time a A-body 8 3/4 was produced? lol. They just are not around in stock form and the ones that are are under cars. We can make the housings from other wider Mopar housings BUT that will have some labor involved too.

500-600 for a full working rear is not out of line for todays pricing.

How much money do you have in a motor? Trans?

DAys of 200.00 rears that actually run are well past. Besides that 20 year ago the rears were also 20 years younger and 20 years less miles too. NOW they are over 40+ years old and will need rebuilding etc.

Watch the used parts out there... Do your home work and spendf money on the parts that will bring you the best bang for your buck and longevity...EVEN if you have to wait another year to save up the money for good/ New parts and service.

Jim

Mighty good advice. Well thought out and right on the money.
 
I get the whole supply and demand concept. I would've payed the $500 - $600 dollars if they had ever called back.
 
I agree. Finding a c-body is cheap plus it will have big brakes if you find it complete otherwise just use the housing, and cutting it down is not that expensive plus you can find aftermarket axles for around 300.00 so you should have about 600.00 total. Just keep your eyes open because it seem to go in spirts that there wont be any a-body housings around then when you are not looking, they are all over the place. GL
 
I guess I'll look around and see what I find for C-body rear. What's involved in shortening it? Anyone know a shop out my way?
 
If you where closer I'd sell you the 8 3/4 Van axle I have.....came out of a 67 A-100...if don't sell it I will find some one to shorten it for me....
 
Some trucks also used 8-3/4 axles so their a place to look for one also. I got lucky recently and bought a 8-3/4 out of a 72 truck and it had a 489 case with a sure grip.

Narrowing it involves cutting it down to length and installing a narrowing jig to hold it straight while you weld it up.
 
I saw the 64x2 posting for the rear. I had the same thought!

If i ever find the housing i guess i will have to find someone to shorten it. I don't have a "shortening jig", my welding skills are meager at best, and after the time and money investment finding one, i'd hate to screw it up!
 
Bolt pattern Should not be a big issue since Mopar has a 5 on 4 1/4 like ford does you must have the small 5 on 4" TIME TO UPGRADE ANYWAY...lol.

Spring perches again NOT a big deal. Cut and paste...lol. :)

Only think you need to watch for is the backspacing of the wheel if thr new rear is narrower. But if your getting new rears to macth the bolt pattern then you can solve that with the purchase OR run a spacer and if needed some little bit longer studs.

Conversion u-joint as mentioned any Auto parts store should have that.

Done.

Only problem now is you have the bad luck FORD product in your Mopar....lol. :) JIm
Dont you mean 5 on 4 1/2?
 
If you shorten and respline any axles you have removed the harden surface so take the toll if your going to run them hard. Just a added thought before thinking you are saving the big bucks when your splines twisted and or snap off the end.

Good luck, Jim
 
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