rear end change / upgrade ??

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cuda67bnl

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I'm looking to upgrade the rear end in my 67 fish which currently has the 7 1/4. I'd really like to upgrade to disks as well. Is there a rear end out of any "modern" car or truck that has the right overall dimensions? Maybe something that comes with a good gear, and posi? Moving spring perches wouldn't be a problem if everything else was okay.
Thanks.

Jimmy
 
I,ve heard that ford explorers have the right dimensions and disc brakes with 373 posi
 
daredevil said:
I,ve heard that ford explorers have the right dimensions and disc brakes with 373 posi
Click to expand...

yea, I have looked into this...

-Ford 8.8" rear axle from a 1995-2001 Ford Explorer is 59.5" wide (between wheel mounting surfaces). Most came with 3.55, 3.73 or 4.10 from the factory. The bolt pattern is 5x4.5.

-65 to 72 A bodies are 55.6 from wheel mount surface to wheel mount surface.

If you can overcome the additional 2 inches in width on both sides, you could make this work. Could be done with special offset wheels.

Good Luck. Post up some pictures when you are done.

Thanks,
Clint S
San Gabriel
 
Quote from the Slant Six site, "The explorer 8.8 is 59 1/2", but the center section is offset about 3" to the right. So I cut 3" off the left tube and used another right axle and now its aprox. 56 1/2" wide. You could use the disc brake model with no problem except adapting the parking brake cable, which looks pretty easy."

The A body axle is 55.6...so 56.5 is only half an inch per side wider. That is not bad. The guy in the article bought his from a pick your parts in Florida for with 3.73 gears and a posi for $89. Hmm....very interesting. I am looking out the window at my wifes Explorer... :angel9:

Thanks,
Clint S
San Gabriel
 
oldmoparsrule said:
Quote from the Slant Six site, "The explorer 8.8 is 59 1/2", but the center section is offset about 3" to the right. So I cut 3" off the left tube and used another right axle and now its aprox. 56 1/2" wide. You could use the disc brake model with no problem except adapting the parking brake cable, which looks pretty easy."

The A body axle is 55.6...so 56.5 is only half an inch per side wider. That is not bad. The guy in the article bought his from a pick your parts in Florida for with 3.73 gears and a posi for $89. Hmm....very interesting. I am looking out the window at my wifes Explorer... :angel9:

Thanks,
Clint S
San Gabriel
Click to expand...
Hey, get the 7 1/4 from cuda67bnl, swap it into your wifes exploder, she'll never know what hit her.
 
oldmoparsrule said:
Quote from the Slant Six site, "The explorer 8.8 is 59 1/2", but the center section is offset about 3" to the right. So I cut 3" off the left tube and used another right axle and now its aprox. 56 1/2" wide. You could use the disc brake model with no problem except adapting the parking brake cable, which looks pretty easy."

The A body axle is 55.6...so 56.5 is only half an inch per side wider. That is not bad.
Click to expand...

The other guy cut 3 inches off the left tube and it ended up 1 inch wider than an a-body rear. If you cut 4 inches off the tube instead of 3, it sounds like it would be the right length overall. But I'm assuming that would put the housing slightly off center again. Would this be that big of a deal? Any chance someone here with an explorer can look at how the parking brake cable works, and see how easy of a fix that would be?

Sounds like I'm gonna be on the lookout for someone local who can cut a tube off and weld it.....
 
cuda67bnl said:
The other guy cut 3 inches off the left tube and it ended up 1 inch wider than an a-body rear. If you cut 4 inches off the tube instead of 3, it sounds like it would be the right length overall.
Click to expand...

So, in looking into this further, the explorer pinion is offset to the left side by 2.25. This means that you could cut 2.25 off of the right side and then use a factory replacement axle left side axle to get an overall width of 57.25 WMS to WMS. If A-Body width is 55.6, then you are still very close, with very little work.

You would still need to do the following:
-Shorten the housing
-Cut and re-weld the spring perches
-(Maybe) cut and re-weld the shock mounts.
-Get a replacement short side axle
-(Maybe) Get new rims with appropriate offset to accommodate 1.125" wider axle per side.

All in all, you are looking at paying a competent welder to do part of this...and you are purchasing a new axle shaft. I would imagine with good "pick-a-part" skills you could do this very cheap ~$200 to $400 max (+ new rims). My Jeep buddies do this conversion all the time, and they stand up to 35+ inch tires with ARB lockers and HUGE torque.

Compare this with the following (Purely estimates, YMMV):
At the spring fling a few weeks ago, I bought a 489 case with 3.23 gears (peg leg) for $80. A guy from this group will ship you an A-body width 8 3/4 for $250 to $300. A set of factory A body 8 3/4 axle shafts can be had for between $100 and $200. Depending on the bolt pattern, brakes would be another $100 or so. So, you could have an A body 8 3/4 for about $600 (VERY cheap, I know). Then a sure grip unit would be another $450...so you are over $1000 for the 8 3/4.

Again, YMMV (Your Mileage May Very).

If you go this route, take lots of pictures, and write it all up.

Sounds like it could be an alternative for folks who do not need the ultimate strength of the 8 3/4.

Thanks,
Clint S
San Gabriel
 
Just my opinions....

The rear of an a body car is pretty darn light. The discs would be "overbraking" for sure...you'd even have to put a brake bias adjuster valve just to keep the rears from locking. Plus narrowing a rear needs to be done right. Take a look at how tiny the rear brakes are on most cars today; the fronts do the work.

Shop around on ebay for guys selling a lot of parts off of an early a body muscle car; they usually don't want to ship & crate big stuff, so if the auction is in your driving range, ask them if they have a rear. I bought some wheels last fall and when I picked them up, the guy was begging for offers on the 323 posi rear....and it was a 68 Cuda :-|
 
I personally think that an 8 1/4 from a mid 70s A-body is the quickest, easiest way to go. Straightup bolt on. They are very reasonably priced, available, and handle up to 400 street hp. I also feel that disc brakes on the rear of an A-body is overkill and unnecessary. JMO, Mike
 
You can never have too much brake.:toothy7:

I'm installing a TSM disc kit on the back of my Dart. it may not be "necessary" but it can't hurt. Adjustable proportioning valves are only about $40.
 
It is easy to find a modern rear that has the same or close width but it will be tough to find a modern rear that has the pinion offset that matches our engine offset to the passenger side on our cars.

Chuck
 
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