rear differential confusion

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mprhoodlum

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I have a 68 Barracuda w/ a 7 1/4 rear end. I'm converting to BBP for front discs and my Magnum 500's. I don't like the idea of drilling the axle flanges for BBP. Let me say for sure, there are no salvaged Mopars in this area and I really don't need the strength and expense of 8 3/4.
I looked into Jeep rear ends and a mechanic/shop owner told me not to bother, especially if it was a Dana and most are. He also said that they had started to replace the 8 1/4 on most off-roaders.
So, I'm considering a Ford rear. Putting in the Explorer seems a lot of work and expense. I can get a Ranger 7.5 for trade on items I don't need anymore. But, if I go to the effort on this swap, I might as well hold out for the Ranger 8.8. I drive a 96 Ranger 4.0 4x4 which is supposed to be the 8.8. The inside dimension from bottom wheel lip to bottom wheel lip is 1/2 narrower than the Barracuda - same measurement. I plan on putting the magnum 500 rims in the Ranger and compare the measurements to the Barracuda.
Anybody know of any other complications? If I can get a rear for $100-150, why not? There are no options on the 7 1/4! Goes anybody know anything about the Ford 7.5? I am not a hotrodder and don't need a lot of strength.
 
an A body 8 1/4 is the way to go, they are a great easy bolt in, strong enough for any driver, no cutting no welding required, just make sure of what ratio you get, some came with 2.45:1
 
The Jeep 8 1/4 is a good option. They solve the bolt pattern problem and they have disc brakes.
 
A Jeep would be ok - except most of the 8 1/4 rears are snatched up by the Jeep people to replace the Dana's. There's no such thing as a FMJ Mopar in the wrecking yards. Pick-a-Part is all 90's up FWD. There are no Jeeps in the wrecking yards - most of them are converted into crawlers or mudders. To show you about what's available from non-dealers, go on Craigslist and look at car parts for Knoxville, TN. Ram trucks are readily available, but that's about all. This is Ford and Chevy country (unfortunately).
 
The 7.5 ford is definitely stronger then the 7 1/4. They put them behind 302 Mustang's thru 1985. Years back, finding a Traction-Loc 7.5 rear was a little difficult. I suppose trucks would be the best place to find one now days. I'd think the 8 1/4 Mopar would be the easiest, most cost effective swap. But, you can't beat the higher numerical ratios readily available with the Ford.
 
mprhoodlum said:
I have a 68 Barracuda w/ a 7 1/4 rear end. I'm converting to BBP for front discs and my Magnum 500's. I don't like the idea of drilling the axle flanges for BBP. Let me say for sure, there are no salvaged Mopars in this area and I really don't need the strength and expense of 8 3/4.
I looked into Jeep rear ends and a mechanic/shop owner told me not to bother, especially if it was a Dana and most are. He also said that they had started to replace the 8 1/4 on most off-roaders.
So, I'm considering a Ford rear. Putting in the Explorer seems a lot of work and expense. I can get a Ranger 7.5 for trade on items I don't need anymore. But, if I go to the effort on this swap, I might as well hold out for the Ranger 8.8. I drive a 96 Ranger 4.0 4x4 which is supposed to be the 8.8. The inside dimension from bottom wheel lip to bottom wheel lip is 1/2 narrower than the Barracuda - same measurement. I plan on putting the magnum 500 rims in the Ranger and compare the measurements to the Barracuda.
Anybody know of any other complications? If I can get a rear for $100-150, why not? There are no options on the 7 1/4! Goes anybody know anything about the Ford 7.5? I am not a hotrodder and don't need a lot of strength.
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Just buy axles then if you don't want to have them drilled, the strength issue you aren't concerned with and re drilling the axles to the BBP isn't gonna weaken the axles at all, have you ever seen what happens to axles being raced in many forms of motorsports? the flanges are machined away to the bare minimum.

Going from the 7.25 to the 7.5 is almost well retarded, i had a 7.25 in a 72 18 car and it didn't blow up even after that car had a different motor.
As for the comment of they put them behind 302 mustangs, well that mustang also has no weight to it, only helping it and a poor comparison to say one is stronger than the other.

Just have them re-drilled or buy new custom axles and be done.

.
 
I have had 3 7.25 mopar rear ends behind /6 engines and they all had lots of slack in them. Seemed that by 125+ K they were clunky and sloppy.

I agree, would hold out for a Mopar 8.25 from an A body or a possibly an Aspen / Volare rear end.

Until you come across your desired rear-end just have a shop re-drill your axles if that is do-able for cheap.
 
I saw the 8 1/4 advertised on here from out of Texas . Problem is - how would you ever ship it? I think I'm going to put a wanted ad on CL for the 8 1/4 Jeep. Either with drums or discs. I'm really not to concerned about the rear brakes. I appreciate the replies.
 
I,d look into an early b 8.75. About an inch wider each side and usually around 150 a pop.
 
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