Mopar 8 3/4 or Ford 9?

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Riddler

Riddler

Project EH-Body
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OK lets leave the hater messages at the door.

I'm building up my 76 Duster. The plan is to have a small block (360 stroked) and a 727. I'm working on planning out the chassis and suspension right now.

I have an RMS Street Linx kit. Which means no more leaf springs. The plan is minitub or tub the rear so I can run some 15x10 rims. I'm planning on some 3.5 or 4.5" backspacing on those. As for rubber, no sure yet.

I picked up a Ford 9" axle for $100. It's complete but needs to be narrowed to fit in the Duster as well as run 15x10 with small backspacing. The center section is open and have a crappy gear (2.75), so that needs to be changed as well.

I've been reading about narrowing the axles and found SW Racecars and Moser sell Mopar 8 3/4" housing ends.

My questions and such come from what I have and what I want. Right now my car has an 8 1/4" rear end. If I used the 8 3/4" housing ends on the Ford 9" will the brake parts mount from the 8 1/4" onto the new axle? If not I've seen Mopar 8 3/4" backing plate and such. So that solves that problem.

My next question would be, since I'm newer to rwd, Is it possible to run axles with the 5 x 4.5" bolt pattern with a Ford 9" with 8 3/4" ends?

Like I said I'm mearly trying to plan this all out so I don't waste money here and there. I've been watching for a Mopar 8 3/4" rear housing and found one locally from a C-body which would need to be narrowed as well. I'm just trying to figure out which way is the best way for me.

I'm guessing the 8 3/4" rear would the easiest to get to work. Buy a complete rear end, narrow it and use new mopar 8 3/4" ends and use the brakes that came with it. Unless of course the C body 8 3/4" is junk?

Thank you in advance.

Riddler
 
How bout keeping the Ford 9" and finding some Ford Explorer rear discs (bolt on)? Lots of them "clunkers" out there. 5x4.5 bolt pattern

Or just buying an 8 3/4 out of a tub and narrow it....5x4.5 bolt pattern.

I'm guessing either way you are gonna get new axles/ rebuilt center section etc....right??
 
Yeah I'm not trying to finish this car ASAP. I'll be taking my time and making sure everything is done correctly.

I didn't know the Ford Explorer is a 5 x 4.5" bolt pattern. If using those parts what housing ends would I need to buy? The 8.8" Ford ones?

I've been thinking about a 8 3/4" and narrowing it. In fact I have found a few semi local with 323 gears and a posi, so if I got one of those I'd have the brakes and the center section. All I'd need to do would be narrow it and get new axles.

Riddler
 
8.8 ford Explorer/Ranger is a c-clip axle. I don't know if those brakes would bolt up to the 9" stuff, but maybe.

You should be able to have Moser or Strange make up axles whatever way you need. I'd just run the 9" ends and get 9" ford rear brakes. The 8.75 is ok stuff too, but why make extra hassle for yourself?

the 9" is the standard rear end in hot-rod buildups parts are more readily available and often cheaper for it than the 8-3/4.

Good luck

Steve
 
I have a bare 8 3/4 B body housing that you can have CHEAP
Just got to get it from Winnipeg to you... and I can get that done pretty low dollar as well. Let me know if you need more details.
 
Riddler, Check with quickperformance.com they are located in Iowa and can help you with anything you need to build a 9in. rearend. Talk to Doug ,they built mine and I couldn't ask for nicer or stronger rearend. Good luck with your build. Tom
 
I guess I thought about using the 8 3/4" rear end housing because I want to stay with mopar brakes.

I have a 9" with a crappy center, so I'd have to purchase a new center anyway. If I can locate an 8 3/4" with decent center with suregrip then I'm golden, narrow up the rear, minitub, and then use the mopar rear brakes.

Riddler
 
just dont get fooled into payin a ton for an 8-3/4...a lot of guys price them high, and if all you can find is expensive stuff then id stick with a 9 inch...a 9 inch housing alone in my parts go for very good money....if i didnt get such a good deal on my 8-3/4 from a member here, then i would have either gone 9 inch or dana...if your gonna build it once, id build with a good foundation in mind (assuming of course that you plan to keep pushing the car)
 
Riddler the majority of Ford bolt patterns is the same 5 on 4.5 that Mopar is so there's no need to try to adapt Mopar axles to a Ford rearend. If you want to stay with a 8-3.4 your best bet is to find a complete C-body rearend and have it cut down to the size you need. That way you have all the brake stuff with it. C-body rears go pretty cheap usually.
 
The 9" is your best option if you plan to have any kind of horse power, the 8 3/4 is a good rear end but won't handle big horse power, that is why Mopar used Dana's in the Hemi and 440 6pack cars. You could get a Dana 60 out of a mid 70's Ford 3/4 ton truck and buy the correct ends but a Dana is 100 pounds heavier than a 9" and you can't easily swap out gears.

I used the 9" housing and brakes out of a 70's F-150, I just redrilled the drums to 4 1/2" bolt circle to fit my Strange axles. The Ford brakes are 11 x 2 1/2 which work great with the 73-76 A-Body disc brakes and stop on a dime.
 
I'm just waiting to hear from a few people concerning some 8 3/4" rear ends that I've sent messages about.

I have a 9" I got for $100. Not sure what it's from and I know the housing is the only good thing on it. That's why I'm debating on what to do. I guess I just need to sit back and wait for a deal to come by.

Thanks all,

Riddler
 
Blownfish said:
The 9" is your best option if you plan to have any kind of horse power, the 8 3/4 is a good rear end but won't handle big horse power, that is why Mopar used Dana's in the Hemi and 440 6pack cars. You could get a Dana 60 out of a mid 70's Ford 3/4 ton truck and buy the correct ends but a Dana is 100 pounds heavier than a 9" and you can't easily swap out gears.

I used the 9" housing and brakes out of a 70's F-150, I just redrilled the drums to 4 1/2" bolt circle to fit my Strange axles. The Ford brakes are 11 x 2 1/2 which work great with the 73-76 A-Body disc brakes and stop on a dime.
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In the future I'm going with the virtually indestructible 9". Your going to have to shorten housing, axles, etc. I want a street strip set up and a set of 1/8 mile gears. The 8 3/4 is getting so expensive and the parts for the 9" are to numerous to count.
 
Yeah, I'm leaning towards the 9" also. Some of the people have gotten back to me and they want $250-$500 for 8 3/4" rear axles. The parts for the Mopar rears are expensive as well.

I have a Ford 9", so I'll just need to get a good center, some axles, narrowed down and then figure out what housing ends I want as well as brakes. I'm thinking I'll prolly just go drum brakes in the rear.

Brings up my next question. Does anyone have a write up on how to figure out the measurements for the rear end? I just want to make sure I'm doing this right and not botch up a measurement and have to find another rear end.

Riddler
 
Riddler said:
Yeah, I'm leaning towards the 9" also. Some of the people have gotten back to me and they want $250-$500 for 8 3/4" rear axles. The parts for the Mopar rears are expensive as well.

I have a Ford 9", so I'll just need to get a good center, some axles, narrowed down and then figure out what housing ends I want as well as brakes. I'm thinking I'll prolly just go drum brakes in the rear.

Brings up my next question. Does anyone have a write up on how to figure out the measurements for the rear end? I just want to make sure I'm doing this right and not botch up a measurement and have to find another rear end.

Riddler
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Put the car on jack stands, rig the wheels, tires in the wheel well where you want them and carefully measure and fill out the form below.

https://www.moserengineering.com go to ordering information and print out the order form, record the dimensions outlined and your set.
 
Uh, Hemis were used with the 8 3/4, so were Max Wedge's-Stage 1,2,and 3. So yes they can handle hp/torque. The 9 inch is/has more parts available, but strength is questionable between the 2.
 
If you happen to run across a `66 to `77 ford bronco rear housing it is .5 of an inch wider that the 8.75 mopar, at the wheel flanges, explorer discs will bolt right up, if you find a complete unit they come with posi and or lockers, 28 and 31 spline, if your lucky enough to find a 31 spline, you can redrill the wheel flange for the mopar( all broncos were 5x5 pattern ) or you can order yukon, moser, currie axles for it. The explorer rear is equivalant of a dana 60 the problem is the pinion is offset 2 7/8 inches to the right, so you`ll have to narrow down the left side only and order an axle accordingly, also the explorer axle tubes are not as thick as the ford nine so welding new sping pads has to be done with a little more care to prevent warppage they also came as posi or open, 327 gears to 373 gears...
 
I won't need to weld spring pads as I have the RMS Street Linx kit which does away with the spring perches.

I just found out DTS is like 10 minutes across the US border from me and they can build me one to my specs for a decent price.

Riddler
 
Riddler said:
OK lets leave the hater messages at the door.

I'm building up my 76 Duster. The plan is to have a small block (360 stroked) and a 727. I'm working on planning out the chassis and suspension right now.
Riddler
Click to expand...
Chrysler 8 3/4.
Twocents.gif
 
Blownfish said:
The 9" is your best option if you plan to have any kind of horse power, the 8 3/4 is a good rear end but won't handle big horse power
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The 8 3/4 is just as good if not BETTER then the 9"..i know guys running 9's in the1/4 mile with them,i'd say they're making horsepower..:-D:-D
 
We could go on and on between the ford or mopar rearends, but it comes down to personal preference. Use what you want/can afford. Some like to use all of the big 3 makers drive train, some like to use a mix, do what you feel like. Just keep in mind that some people may look "down", on the "brand x" rear, but you can say you did it your way and that is all that matters.
 
Ya know both Mopar and Ford both use a 4 1/2" bolt pattern wheel.......
You can buy brand new axles from Moser for a little more than these collector idiots want for their throw aways!!!!

Whatever you do stick with the Moser gang, they're very smart people
(they even have a Mopar guy working there!!!)

Since you already have the nine inch...use it

OR

Buy Moser's fabricated 8 3/4 housing and have them fill it up like you want...

OR

Buy their Dana 60 made to order...............
 
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