A body rear axle into F-body??

[greymouser7]

Do people do this simply re-welding the leaf spring brackets?

How do you figure out what off-set you would need to make this work in an FMJ body car?

Any input would be appreciated.

 

[kkritsilas]

I don't recall exactly, but A body rear axles (I am going to assume you mean the entire differential), are too narrow to fit an F/M/J. The closest rear for the FMJ is the '66-'70 B Body rear in terms of width. Spring brackets are off by 1/4", but I don't remember if this is per side, or overall.

There are postings here that give the widths of the various rear ends for the different body sizes (A, B, C, E, F, J, M). Hope that someone can post the link.

Kostas

P.S. Found one thread on this here:

http://www.forfmjbodiesonly.com/classicmopar/showthread.php?3492-F-M-J-rear-end-widths

 

[gtsdude]

Yep B body rear 67-70 will bolt right in, you can use the shock mounts also to get rid of the rubber F body mounts. I have one in mine, just need to upgrade rear springs now.

 

[Blackbirdsrt78]

How they do it is tub the wheel wells. relocate the spring perches and mounts. its for using VERY wide tires that don't sick out from the body like mine do. I have only seen it done for drag cars. They don't fit until you do a crap load of work to the car.

 

[slant6billy]

The perch is not for an iso clamp, but workable on the 62- 70 8 3/4. The wheel flange is a 1/4 inchwider on either side, but the perch is narrower by 1/4 inch. Use a ratchet strap to pull the springs at each other. The driveshaft yoke is .66 inch closer to the trans. I'm building another 8 3/4 for my F with a 742 case, plus a set of 15 by 12 rims. So it will stick out and be severely jacked to accommodate.

 

[Blackbirdsrt78]

It was always my understanding that the B-body rear axles are the more easy to find. I was trying to do this when I had the barracuda. A body axles might as well be made of gold. John you are better off having a shop chop and weld a housing you have and get custom axles made. before using an A-body rear. would be cheaper I think

 

[slant6billy]

I would guess without looking at production numbers, 9 years of B body coupes and 4 doors, would be the highest number of rears available. I have heard the 62-64 are tapered? That still leaves 6 years. The other option, the ford 8.8 out of the explorer. It is much narrower and requires welding the perches from summitracing.

 

[greymouser7]

Billy the B body axles that fit with a half inch off set-near perfect is 1966-1970.

After 1970 model cars, our Mopars got fat and wider axles my friend. (But don't call them fat in front of anybody!)

 

[Mcfly68]

The exploder 8.8 has to be narrowed to fit an A body, but for the F, just the perches have to be moved..it is actually a little wider than the B 8.75, but worked out real well in mine with the bullit rims I am using due to the greater off set. The great thing about the 8.8 from the exploder is...31 spline axles, 3" axle tubes, disk brakes, gear ratio's of 3.55, 3.73, or 4.10 with posi...and dirt cheap ( I paid $150 for mine with new rear pads and rotors already on it)!!!! So for the sake of welding on $30 worth of perches..you get a rear that is stronger than a 8.75, more aftermarket support and scrap yards full of 96+ exploders to pick them up out of for cheap...until all the jeep guys grab them that is

 

[kkritsilas]

The Ford 8.8" is emphatically NOWHERE near as strong as the 8/75". Put a Ford 8.8" behind a brig block 440 or Hemi(assuming it is running well), and you will shortly be digging out shrapnel out of the rear sheet metal and road. You may have an argument that the Ford 9" may be as strong as, or possibly even stronger than the 8.75", but the 8.8 is nowhere near that strong. It is fine for small blocks, just like our 8.25" is. Top dog is the Dana 60, as used behind manual transmission Hemis and 440 Six-Packs/Six Barrels.

Sounds like I contradicted myself, but the 8.75" was used behind some Hemi and 440 automatics; the Dana 60 was always used for manual 426s and 440s, and sometimes even for the automatics.

 

[greymouser7]

The Ford 8.8" is emphatically NOWHERE near as strong as the 8/75". Put a Ford 8.8" behind a brig block 440 or Hemi(assuming it is running well), and you will shortly be digging out shrapnel out of the rear sheet metal and road. You may have an argument that the Ford 9" may be as strong as, or possibly even stronger than the 8.75", but the 8.8 is nowhere near that strong. It is fine for small blocks, just like our 8.25" is. Top dog is the Dana 60, as used behind manual transmission Hemis and 440 Six-Packs/Six Barrels.

Sounds like I contradicted myself, but the 8.75" was used behind some Hemi and 440 automatics; the Dana 60 was always used for manual 426s and 440s, and sometimes even for the automatics.

checks with chart! (everything that I have ever read)

the 8.8 sounds like a viable budget alterative to the 7 1/4 fo sho! that is cheap!!

 

[Mcfly68]

a mustang 8.8 is no where near as strong I agree...smaller axle tube, smaller axle shafts,smaller bearings....look into the exploder diff...it is alot more robust and a lot different than the mustang and ranger versions....survives very well behind big blocks with very few mods... (weld the press in axle tubes to the center section, rear cover with preload adjusters, change the flange to 1350 u joints).I know a bodies running 8.8 behind very stout RB's..granted they have a few extra mods to it, but nothing more than you would do to any rear in strip car..yes it isnt a dana 60 or a ford 9.....but a lot better than a small pinion 8.75 and about 1/4 the cost.

 

[Mcfly68]

http://www.forabodiesonly.com/mopar/attachment.php?attachmentid=132958&stc=1&d=1267726875

This is the difference between the 8.0 dodge and the exploder 8.8.....8.0 is tiny compared to it

 

[kkritsilas]

greymouser7:

The mopar 8.25 is a budget alternative to the 7.25. Even up here, in the land of salt that eats cars, a fully functional 8.25" can be had for about the same price as the 8.8" Ford. If you get the 8.25" from an F, M, or J, you don't have to mess with anything, spring perches, wheels with different offsets, etc. Consensus is that they are strong enough for just about any small block on street tires. Will probably break with slicks, or behind a big block.

Kostas

 

[kkritsilas]

This is confusing. Chrysler doesn't have an 8.0. Are you referring to the 8.25" or the 7.25"? The 7.25" is good only for six cylinders and stock, low power/2BBL 318s, The 8.25" was good enough to be used under M body police cruisers, and pursuit vehicles, as well as 1/2 ton and 3/4 ton pickups and vans.

Nice picture, but essentially meaningless. The outer housing really just keeps the working parts in alignment. The axle diameters, the splien count, the size of the ring gear, pinion gear, the sizes of their teeth, the overall amount of metal and the quality of the metal used in the gears are far more important that the size/shape of the outer housing.

I suspect that the mods that you propose for the Explorer 8.8 would make your inital $150 investment come out to be substantially higher in the end. Along with needing non-Mopar factory wheels. Could be wrong on that, I guess.

Kostas

 

[greymouser7]

I think many of the Ford wheels match right up- 5 lugs on 4.5" spacing. (both brand trucks have been 5 on 5")

He said $150, which I would think would be super cheap, as people here in Florida are asking over $400 usually for 8 1/4 axles. I dunno if the 8.8's come with rear disc brakes.-the jeep Cherokees, commanders, grand pubba Cherokees,-that whole line of vehicles do, but are 29 spline after (96??) and people are crashing jeeps as fast as they make them.

When I look at later model jeep rear axles they are still expensive. I bet Kostas, that the mods would get expensive as well, or that Mcfly's $150 price might be regional. FmJ body axles around here are rare, and still expensive-for my-tastes usually, if I were to buy one, it would have to have sure-grip.

 

[Blackbirdsrt78]

carefull getting those rears form the jeeps the carrier is off center on some. make sure both axles are the same length.

 

[ramenth]

Keep an eye out for the most widely overlooked rear in Chrysler's history: the ubiquitous 9.25" used in just about everything. Dakotas, Durangos, Ramchargers, half tons and bigger, B-Vans and the like. Cheap enough (usually) to get, hardly any mods to make work.

By the way, Ford may use the same bolt pattern and offset (sometimes), but the pilot register is smaller. They have to be hogged out to work.

 

[gtsdude]

Here is some reference info for the 8 3/4

Housing widths, flange to flange

A BODY
'66-'72= 52 5/8"

B BODY
'62-'63= 53 1/4" (And '64 Max Wedge)
'64 = 55 5/8" (Exc. Max Wedge)
'65-'67= 54 1/4"
'68-'70= 54 15/16"
'71-'74= 57 7/8"
'71-'73 wagon= 59 7/16"

Spring perch widths (center-to-center)

A BODY
'66-73= 43"

B BODY
'62-'70= 44"
'71-'74= 47.3"

Rear end widths, drum-to-drum:

A BODY
'66-'72= 57 1/8"

B BODY
'62-'63= 58 1/2" (And '64 Max Wedge)
'64 = 60 7/8" (Exc.Max Wedge)
'65-'67= 59 1/2"
'68-'70= 60 1/8"
'71-'74= 63"
'71-'73 wagon= 64 3/8"

 

[gtsdude]

On the exploder 8.8, that is a very good alternative and in my area anyway fairly cheap too. Disk brakes and limited slip are a plus if you find one equipped with them. Bolt pattern should be the same 5x4.5