Does anybody happen to have the flange to flange width of a 1955-56 Dodge or Plymouth rear axle handy?

Housing width or drum-to-drum (overall) width?

The drum-to-drum width for the '55-'56 Dodge/Plymouth is 59 15/16". The spring perch centers are 41".

Thanks John. Overall width, the info was just what I was looking for.

If you're looking for a later model to swap in, the '65-'67 B-body is 59 1/2" with 44" perch centers.

Thanks again John.

I’ve been kind of looking for a 55-56 Dodge or Plymouth to wrap the 1st Gen Hemi I’m building with. No luck so far but something will probably turn up.

I figure if I stumble on a rear end (or just housing and axles) the right width and price I’ll probably pick it up just to have it on hand. While I’d prefer an 8 ¾” I don’t think I’d pass up a 9” Ford if I stumble across one. I did a quick check on the prices for the parts I’ll need to set either one up and they run about same.

We have a swap meet coming up in a couple of weeks so I’ll throw the tape measure in my pocket LOL.

Lot of people use the Ford 8.8 out of an Explorer in these applications. 1991-2003 Ford Explorer 8.8-Inch Axle - 59.625 inches

I ran a 8 3/4 from a mid-'60's (I think '65) B- Body in my 440-powered '56. Moved the perches and it worked great.

I have the same set up in my '57. Works great and the 8 & 3/4 rear is easy to work on.

“…….Lot of people use the Ford 8.8……..”

For the last few years that’s kind of been one of the hot setups, and I’ve got to admit their becoming a lot easier to find than the 8 ¾ and 9”. I like the idea of using a rear end with a drop out center section for this project however. I’ve narrowed the rear end ratio I’ll be using to 3 choices; 4.10, 4.30 and 4.56. The final decision will be left until I figure out what tire size I stuff under the rear end. If I choose poorly and want to change, it’s a whole lot easier with a drop out center section.


“……I have the same set up in my '57. Works great and the 8 & 3/4 rear is easy to work on……”

I’m running a 9 ¼ with the cone type sure-grip of unknown origin in my 57. Fortunately I’m happy with the 4.10s and A833 overdrive transmission. You’re right about the 8 ¾ being easy to work on, especially a gear change. Relocating spring perches, setting pinion angles, plumbing and emergency brakes, even building a drive shaft if necessary are not really hard jobs but they are time consuming and something you only want to do once on a project. Once you have it done you pretty much live with the housing you’ve built. Doing a gear or carrier change at that point gives you 2 options; pull the whole housing to make it easier to work on or fight doing it in car. I’m getting older and neither option is real appealing………course it might be a good time to teach my grandson all about rear ends


“…….I ran a 8 3/4 from a mid-'60's (I think '65) B- Body in my 440-powered '56…….”

Just curious, what are you running for a front suspension and rear springs?

If you are only going to be doing this once, might be even easier to have a shop do the gear change on the 8.8. Still probably come out cheaper than finding and buying am 8 3/4 and odds are you won't be finding the ratio you want already in it so you still will be doing a gear change, unless you already have those center sections on hand and ready to go.

Not to mention disc brakes are easy to find on an 8.8. if you want them, not so much the other options mentioned.

I haven't paid for a gear change since 91, so I dunno the cost there, ymmv.

“…….I ran a 8 3/4 from a mid-'60's (I think '65) B- Body in my 440-powered '56…….”

Just curious, what are you running for a front suspension and rear springs?

I went through the stock front suspension and kept it. I had the opportunity to clip the front of the frame but after the time spent building the engine, swapping drivetrain, differential and more, I was getting tired of working on it and just wanted to drive it. I'm embarrassed to say I don't recall the specifics of the rear springs, I worked with a local suspension shop and followed their recommendations. Took a ton of build pictures in case they could help some else building a similar big block 'project but none of the rear and springs. Go figure

Thanks Sniper, what you are saying makes perfect sense, and is not out of the question, based on what I can find locally. Since your original comment I have also been pricing out carriers and ring and pinion sets for the 8.8s along with the 8¾ and 9” (so far everything is pretty comparable). You right about my wish list for ratios not necessarily being factory available. Your point about disc brakes is also a consideration although conversions for the Ford 9” are pretty easy to come across, and I know they are out there for the 8 3/4 (just haven’t priced them out).

Normally I wouldn’t have given a second thought to the rearend this early in the process. Up until a couple of months ago there was an old time mom and pop junk yard nearby with a LOT of 50-60s parts cars to choose from. With the death of the original owners the kids elected to sell all the cars in the yard and they have been moved out to a couple of yards up north.

With that source gone I figured it might be a good idea start looking around now for something that will fit the car I plan to eventually end up with (55-56 Dodge or Plymouth). I still have a few local sources to check by I needed an idea on the width I’d need.

Our market out here is a bit different than back in the Mid-West. Without having the rust issues out here there are still a lot of older vehicles around and sourcing an 8 3/4 or 9” is still fairly easy. That being said, while the old cars don’t usually show up in the pick-a-part yards the vehicles with 8.8” do.

So basically everything is still on the table and I do appreciate your input.

56 Royal that’s nice! Bet it’s fun too

As I mentioned above, I’m looking around for a 55-56 Dodge or Plymouth to stuff a drive train I’m building in to; first Gen 354 HEMI and 46 RH transmission and a later rear end (LOL).
My original thought was the same as you, doing a front clip. After thinking on it a bit I’ve been wondering how I would like it with the stock front suspension (rebuilt of course) with disc brake and Power Steering conversions.


You are probably the perfect person to ask this question to. How do you like the stock front suspension? Do you happen to remember what you used for front springs?

Front springs are stock but new. Scarebird offers a disc brake conversion. https://scarebird.com/index.php?route=product/product&path=64&product_id=175
I didn't install power steering, just toughed it out with the manual set up. Actually, I liked the natural feel on the road, though parking could be challenging. I kept the original, large diameter steering wheel, so that gave me some leverage. The ride with the stock suspension was quite comfortable and controlled.

I have the '65-'67 B-body rear in my '56 Plymouth with the spring perches moved inboard. The original shocks mounted on the spring perch but there's no reason why you couldn't use the later lower plates and use a longer shock.

As to the Ford rear, is the pinion offset the same as the Mopar? Worth mentioning.

Be aware that a 57 Dodge and a 55 & 56 are different critters. The 57 was "all new" and the power steering on a 57 only fits a 57-60, and leaves a lot to be desired. The steering box is part of the steering column, (both manual and power, but the power box is huge) and it all goes in and out of the car through the car's interior. Because of the 57's torsion bars and the location of the steering box, you are very limited to other power steering options. Something you may want to keep in mind as you look for a car.

We installed an 8.8 into my son's 57 Dodge wagon (along with a 5.7 and its auto trans). The 8.8 we installed was a disc brake with a 3:73 limited slip. it was originally a coil spring rear end (I think) out of an Explorer. The wheel track was pretty narrow for the wagon, he had to get wheels with the proper off set. We also had to cut and open up the drive shaft tunnel about an inch for driveshaft clearance (I believe it was because of the driveshaft diameter rather then the pinion offset, but it was several years and several builds ago.

“……Front springs are stock but new. Scarebird offers a disc brake conversion. https://scarebird.com/index.php?route=product/product&path=64&product_id=175

I didn't install power steering, just toughed it out with the manual set up. Actually, I liked the natural feel on the road, though parking could be challenging. I kept the original, large diameter steering wheel, so that gave me some leverage. The ride with the stock suspension was quite comfortable and controlled…….”

Thanks 56 Royal. That’s the info I was looking for. I’ve already been looking at the Scarebird conversion. They appear be the only game in town right now. AAJ used to make a kit, but I don’t think they’re in business anymore.



“….As to the Ford rear, is the pinion offset the same as the Mopar? Worth mentioning…..”

Honestly not real sure John, but something else to definitely consider (and research).



“…..Be aware that a 57 Dodge and a 55 & 56 are different critters. The 57 was "all new" and the power steering on a 57 only fits a 57-60, and leaves a lot to be desired. The steering box is part of the steering column, (both manual and power, but the power box is huge) and it all goes in and out of the car through the car's interior. Because of the 57's torsion bars and the location of the steering box, you are very limited to other power steering options. Something you may want to keep in mind as you look for a car……”


Thanks poorboy, and yes I am definitely aware of the differences between the 55-56 and the 57-60 car (actually if I’m not mistaken the same steering box was used thru 1962 on the Chryslers).

You’re right about them leaving a lot to be desired. In addition to being a PIA to get in and out the road feel is horrible……it was the reason I went with manual steering when I originally built my 57 Plymouth.
I did a “Youturn” Power steering conversion on my 57 a couple of years ago that used a Ford truck PS box. It was a fair amount of work. A large part was making some modifications for the clutch linkage as it wasn’t designed for manual shift cars. All in all it was worth it and I’m really pleased with the results. The company is now also making a PS conversion for the 55-56 Dodge and Plymouths and that’s kind of the direction I’m looking at going.

Rusty Hope shows a kit for the 56, I have installed one of their kits in my 51 Plymouth,

https://www.rustyhope.com/mopar-disc-brakes

Link to my write up of the install.

https://p15-d24.com/topic/56787-weekend-work/#comments

I put an E-Body 8-3/4 under Kayse's 55 Desoto.
It's about an inch wider than the original rear end but the spring perches lined up perfectly on the leaf springs.

In '55-'56 the Chrysler and DeSoto are different animals.

Yes in some respects, but use many of the same sheet metal and other parts.
Looking at rockauto most of the chassis parts they list are for either brand car.

I would have normally started another thread but this one got off track enough that I figured I’d just post my next question here too.

I had just assumed that the 55-56 Dodges and Plymouths used a rear sump oil pan like the 55-56 Chryslers and they didn’t start using the center sump pan until 1957 when they started using the torsion bar suspension.

I recently came across a picture showing what was purported to be to be a 56 Dodge oil pan and it was center sump.

For the guys who have a 55-56 Dodge or Plymouth is the stock pan center or rear sump or if you did an engine swap is there enough room to use either style pan?

The 1st gen Chrysler HEMIs only used the center sump pans in 57-8, they’re out there but if I need one I suspect I should start looking around now.

.

'56 Plymouth FSM shows a front sump or center sump.

I have a 54 Dodge truck factory service manual, it shows both a 241 Hemi and a 331 Hemi, and the illustrated pictures of each show a front sump pan on both motors. The flathead 6 is also a front sump pan. Maybe another option?

Looks like front sump is V8 and center sump is flathead 6, according to my /56 Plymouth manual

Thanks everybody. Looks like I'll be putting a 392 oil pan on the list of things to look for.

.

the 241 i have on the shelf looks to be a front sump as has been shown.
that engine and a bunch of chromed parts i have stashed in the upstairs "junk room" is promised to member CrowBait.
hopefully, i live long enough to see him do something with that engine.

Interesting video on swapping in the common Explorer rear end.
https://www.youtube.com/watch?v=uMk7EOO3k24

I saw that video on another site. A few issues with some of his claims about the original axle, but over all a decent show. IMO, for the stock flathead, the only real issue I have with the original axle is the non-self energizing drums on it. Gear ratios might be a bit high, but an OD trans is probably a better option than a gear ratio change. Of course, it's cheaper to swap in an Explorer axle than to source an original OD trans, lol. Though there is an adapter that allows you to slip an A833 (or an A833OD) in there. But that's another can of worms dealing with no parking brake.

Yes he is not well versed in what's available for the vintage cars but it would be nice to have the parts availability (salvage yard and parts store) of a modern vehicle such as an explorer and F150.

Brake parts are easy to find, not inexpensive though.

New gears? Well NOS is around but ratio choices are real limited.

Limited slip? lol, no.

bearings and seal, common.

it's the little stuff that can get you, like the shims used to set bearing preload, you will be rolling your own there.