'66 Fury rear a good choice?

[austinsailor]

I'm still gathering a few parts for my '42 2 door sedan and was thinking of a different rear axle. The original rear axle with the 4:11 would probably work ok, but I'm sure there are better choices.

I have the chance to get 2 '66 Furys pretty cheap, actually can make a few hundred just stripping and crushing if it came to that. Rears should be 8 3/4 with bigger brakes than the 42. Width is listed as less than an inch different. Ratio is unknown, but probably in the 3:55 range. With a 251 with speed parts, high compression and 3 speed od transmission, I'm wondering if this is something I should do?

Thoughts?

[Young Ed]

Let me know if you get either one. Couple parts on Dads 66 wagon could use improving.

[Oldguy48]

I used a 8 3/4" 3.55 ratio rear in my P15. The housing was from 1969 Roadrunner (at least that's what the guy told me that I purchased it from), with 10" drum brakes. The "pumpkin" was a 741 case 3.55 ratio, from an unknown vehicle. I took the whole works to a local machine shop to get new axle bearings, seals, etc. installed, and the center section inspected for wear. Turns out, the spider gears, shafts, etc, were shot and although I tried and the shop owner tried, we could not find new replacement parts. I ended up having the shop install an Eaton Tru-Trac differential. I wanted to get new brake drums, but ended up having mine blasted and turned, because they seemed to be hard to get as well. (I ordered new ones from my local NAPA store, but they were Chinese garbage that would not fit) All in all, I spent over $1000 to get the 8 3/4" in shape to install. And now I have an annoying pinion seal leak even though a new seal was installed. Not trying to steer you away from a 8 3/4" unit, just beware that you might have to spend some cash if yours needs repair. Perhaps you'll luck out and not have to do any repairs. Good luck to you!

[austinsailor]

one is a 2 dr ht, Spot Fury, I think, the hot rod one with the desireable console and no rust, minimum dents, 318. Other is a 4 dr ht, 318 and some rust. Both torque flutes.

He was disposing of his dad's car lot ( buy a junker here, finance it here, find it here again in a month when it's repossessed) when he died. I convinced him those two were better not crushed, somebody would pay more than the crusher, but the last 18 months have proved me wrong. I thought sure someone would want a dent and rust free 2dr ht to build a muscle car. Not yet.

I bought a 71 Fury 3 for $300, sold the drivetrain for$525, body for $180 at the crusher, and I got the wire wheels I wanted. Guess I can do the same with these.

Ed, there would be a front clip he could use, probably not much else.

But I'd have two axles to work with.

[Plymouthy Adams]

good possibility that the rear gear could be a 2.94 or a 3.23...very popular ratios for that yar car...the 66 Fury of my younger days was a 2.94 Posi..

[austinsailor]

that would result in about 1800 RPM at 70, probably not ideal.

[Plymouthy Adams]

if you still powering with the flathead..no be a bit high for that..you could probably get by with a 3.23 if you live in a relativley low area without hills etc..most all here have settled for the 3.55..look to a Dkaota for that..I have a 3.55 in this 2004 Dakota...not the ratio I want so am not using it..but sad to say it is 6 lug so useless to most folks..sending it out for a bolt pattern change is a bit expensive..and to my knowledge..the early Dakota 5 lugs have different spline count. Look to the truck/van series if you got to have the 3.55 they were most popular..mid ratio..some vans got 3.23 and some trucks got he 3.73..but the 3.55 was most popular..

[austinsailor]

251, 9 to 1, dual 2 bbl, hot cam, ported, tube headers by Langdon and a '50's od 3 speed. 4.11 is to low, 2.94 is too steep, 3.55 would be good, maybe 3.73.

[Young Ed]

I cant believe no one wants that rust free 66 hardtop. Bring something like that to MN and it'd sell quick. Good market for rust free cars around here.

[JerseyHarold]

Too bad you're so far from me. I'm looking for a good rear bumper for my '66 Sport Fury. Oh, well.....

[austinsailor]

I mailed a front bumper from a 53 pilothouse across the country for $23, so it might not be a far fetched idea. I don't recall what shape the bumper is on on both of them, but when I get home next week I should look.

[austinsailor]

Tim, I was thinking about your comments about the tall gears of the era. I bought a new Baracudda in 1965. 235 hp 273, 4 speed and 2.25 or so gears. It would do about 45 in first, 80 in second, way past 120 in third. Who would know in 4th?

My 251 will be barely half the hp, might not push that tall of gears so well. It's become obvious I should chech the ratios before getting too serious about it.

However, it's pretty simple to stick a rear end in and find out how it works. Probably have to invest in a driveshaft unless I could get the existing one to match some way.

I have swapped rear ends in Chebbys, just torch off the coil spring junk, cut the mounts off the old rear, weld them on the new former coil axle, bleed the brakes and drive away. U joints matched on those, probably not here.

[Plymouthy Adams]

as most all MoPar wheels are hub concentric (think alignment and true ability to transfer some serious torque without damage) the wheel/hubs have been this way since who knows when and will all interchange even up to the modern wheel..it is my opinion to stick with MoPar swaps..now Ford is common for the bolt pattern but not hub sized the same as MoPar...Chevy..just a lot of work and unless you swapping fornt suspenison will require dual pattern spare wheel/tire, have seen three or four this week beside the road..seems they just fall out...The Mopar 8.750 is availabe in gear ratios I know from 2.76 and up...get this housing and you need but pull the axles for a quick change of any rear combo pumpkin you want in just a few minutes..only thing to keep in mind that though the interchange is quick..not all will be adjusted for freeplay the same so do watch that you get this right on assembly.. .008 to .018 and you be fine. Some units will get a bit of bearing work in this area and the lock tab is often left off by the PO..so do watch for this..

[Andydodge]

I'm always looking for a 64-66 318 poly to eventually replace the one in my 40 Dodge which is a 1962 version. I want to be able to use the alloy 727 or 904 and the 64 on poly will allow me to also use the poly speed gear I have.........any chance you could post the poly to me in Oz........a plain brown padded bag would be fine.........lol............andyd

[austinsailor]

Come visit and we'll slip it in your suitcase. Bring a big one.

[greg g]

you can probably ship the bumper by bus. Its pretty cheap for bulky items. Its a Terminal to terminal deal so there is some footwork needed. But its an option for stuff too big/heavy (expensive) on UPS or Fed EX.

Wouldn't get the engine to OZ though.....

[austinsailor]

I sent the bumper above by us mail, if it'll go, it's surprisingly cheap.

[littlemo]

Any additional info on the Sport Fury ie. is it still for sale and how much??? Your pretty close to me, and I'm definitely interested, if; "the price-is-right" !! Add; PM me or e-mail at lilmocass@yahoo.com Cass, alias littlemo...

Edited December 31, 2011 by littlemo

[Rusty O'Toole]

I don't see the sense in installing a 45 year old rear axle no matter how cheap. You can buy a much newer Jeep or Dakota rear axle at the Pik a part for a few bucks more.

[Plymouthy Adams]

actually..the Dakota rear gears and most rear gears in this area are in the 250.00 range...and for a late model...not worth the effort and trouble to use..they are six lug..either change the pattern by sending out to a machine shop or buy an older rear gear...even the early Dakota 5 lug is now 20+ years in age..and they have smaller brakes also ont he average....axles as to best of research are not interchangable without a lot of work as the spline count is different between the early and lates...then you can say yeah, the new Dakota is now 5 lug but its at 5" bolt circle...and the Jeep..the better choice for both the right bolt pattern and newer in age..but Jeep parts around these parts are even a bit higher it seems..and then you have the biggest difference of all..ratios and their availability..not eveyone wants a 3.55 the 8 3/4 has readily available gears to suit any build one may want to endeavor..PLUS the 8 3/4 will live forever due to the legendary muscle car application...

[blucarsdn]

I'm still gathering a few parts for my '42 2 door sedan and was thinking of a different rear axle. The original rear axle with the 4:11 would probably work ok, but I'm sure there are better choices.

I have the chance to get 2 '66 Furys pretty cheap, actually can make a few hundred just stripping and crushing if it came to that. Rears should be 8 3/4 with bigger brakes than the 42. Width is listed as less than an inch different. Ratio is unknown, but probably in the 3:55 range. With a 251 with speed parts, high compression and 3 speed od transmission, I'm wondering if this is something I should do?

Thoughts?

If you check the rear tread width on your '42 I think you will find that it is in the 54-1/2" range, backing plate to backing plate... The '66 diff with it's added brake size will be to wide for your car..

When I started gathering parts and info for the rebuilding of my '39 Ply conv cpe I talked to a man that had upgraded the running gear on his '39 Plym conv. cpe.. He had used later model Mopar front and rear, which put his wheels to far out in the fender wells.. His only choice was to use very narrow tires on six inch wheels.

You should probably be looking for something in the Volare size, they make good donor cars for upgrading '30/40 model Mopars, and other cars of the same era... The front end under a Volare is a very popular up-grade for early vehicles....

For gearing you should opt for something in the 3.50/3.90 range if you have a warmed up flat head... Your listing states that the car has an overdrive so that would mean that you need to stay in the 3.90/3.50 ratio range for good highway cruising in the 70 mph range.

My '39 has 3.23 gearing in a GM 10 bolt from an early Camaro... 54-1/2" backing plate to backing, with 3.5" drums and 7" rims, P205R6015 tires, I have no fender clearance issues.. My engine is a 330 HP V8.

Edited January 2, 2012 by blucarsdn

[Plymouthy Adams]

actually the backing plate to backing plate measurement is NOT the best method in measuring the width of the rear end for swapping..case in point..2 1/2 x 11 inch brakes will have a backing plate to backing plate two inches less but still be dead on the flange to flange measurement..this is where you must pay most attention especially if you plan to have the exact track as your original which is very important if running stock wheels....flange to flange being equal to your original is what sets the track distance..not the backing plates..keep in mind also that if you are going 8 1/4 later MpPar gear..if you get a early Dakota with small brakes, you can swap the backing plates even from the 7 1/4 which were more common to the larger rear wheel drive Diplomats and such and get the larger brakes...

[austinsailor]

there is a diff conversion thread with a chart which shows the 42 and the fury at less than an inch difference in track width. I guess there is the question of where this is measured.

As to wheels, I've got a set of aftermarket wire wheels for it that came off a 71 fury3, so I think some time with a tape is the only way to sort it all out.

But, you guys have given me plenty to think about.

There is also that 55 Desoto I plan to look at. might be a choice to consider, after all, it started with a std overdrive, so the ratios should be appropriate.

[blucarsdn]

It just might be that a vast majority of of the car guys are not aware of the fact that a conventional manual trans w/OD will have a much lower gear ratio than a non OD vehicle... Generally speaking the OD ratio will be in the 3.90 or lower range.

The modern cars that have OD transmissions are generally automatic's AOD or multi speed, 5 or 6 speed, manual transmissions. These cars had/have an engine with much higher horse power, therefore they can pull the higher rear ratios.

When selecting a rear end from a late model donor car, there are a lot of factors that must be kept in mind.

[moparmonkey]

I recently found a '65 Polara at the local Pick-n-Pull, this was a 4 door but its a C-body like the sport fury's. Flange to flange you'll find the early C-bodies are 56 3/4", they're almost the same width as the E-body Challengers and 'Cuda's. They're usually a little wide for the 40's, the lend themselves better to mid to late 50's swaps. But, if its only a couple of inches wider you might be able to run it anyway depending on your wheel choice. Most rims nowadays have a much deeper backspace, which allows for a longer axle. An extra inch of backspace per side is usually pretty easy to come by, as long as you're not planning bone stock wheels.

A lot of those cars had 11 drums, the 8.75" rear I pulled out of that Polara wore 11"x2" brakes. Pretty handy, and the parts are pretty valuable. But, the C-body's were more cruiser than musclecar, and the rear end ratio's are usually in the 2.76 to 3.23 range. With a 318 I would suspect freeway gears, but you never know. And if it isn't a single legger, it will be the more desirable clutch type sure-grip.

Still, I think the 8.75" rear is one of the best out there. Easy gear changes, just swap the 3rd member. If you get an extra chunk or two, you can swap gears if you're planning on going racing, or for a long drive. The axles don't even have to come all the way out, just a few inches. Weld a drain bung into the housing and the whole thing can be done in less than an hour, with not all that much mess. Not as strong as a Dana 60, but unless you're running big horsepower they're more than strong enough.