A body 8 3/4 or B body 8 3/4 ?

-
69fstbkcuda

69fstbkcuda

Well-Known Member
Joined
Sep 10, 2011
Messages
88
Reaction score
2
Location
West Virginia
hey guys, I gave my right arm for an A body 8 3/4 rear end for my 69 cuda. I converted the front from a small bolt to big bolt. I was talking to a local gear head and he said that I should have went with the B body rear end. He said the width of the front with the big bolt pattern would be wider than the A body 8 3/4 and the width from the B would match.

thoughts and opinions please, thanks

"you like them spinnin tires"J.D.:burnout:
 
A b body rear is wider that an a body & may require you to move & reweld spring perches & you will have to get wheels with more back space so they don't rub the wheel well or lip. You could just buy the BBP axels & B body brakes & use your housing & sell off the small bolt stuff.
 
69fstbkcuda said:
hey guys, I gave my right arm for an A body 8 3/4 rear end for my 69 cuda. I converted the front from a small bolt to big bolt. I was talking to a local gear head and he said that I should have went with the B body rear end. He said the width of the front with the big bolt pattern would be wider than the A body 8 3/4 and the width from the B would match.

thoughts and opinions please, thanks

"you like them spinnin tires"J.D.:burnout:
Click to expand...
Really , that does not sound right . Think the gear head is talking out his *** , or he needs the a body 83/4 . Think wheel offset will have more to do with it , but maybe I'm talking out my ***
 
Never heard of the big bolt front being wider. Also there are 3 different width b,s depending on year. But yes the 66 to 70 rear is only about 1 and 1/8 inch wider each side. but perch spread is 44 instead of 43 1/2
 
Everyone has an opinion.This is another-coulda/woulda/shuuda.Anytime you start to frankenstein any type of vehicle you need to look to the end result and be realistic as to what you want out of the car.Regardless of what anyone says-you have picked the best all around rear for your car.It has held up to all the Chrysler engines-that in itsself is the best testimony available.Hindsight is 20/20 and that is what you are dealing with now.Buy new axles with the B body backspacing and use B body brakes-problem solved.Or you can do the same as one of the racers.He bought a Dana 80 from me and is going to cut it down.Anything is possible with enough time and money.Is a Dana really what you need? I doubt it.Again-you have the best all around rear for your car.You need to understand that bench racing-or bench building is relative to whom is talking.
 
If there's any difference it's sure not noticeable. I converted the front brakes on my 68 Cuda to 74 Dart disc brakes (big bolt pattern) and although I have not measured anything it sure doesn't look like the front track is wider. I have a stock drum setup laying in the garage and next time I have a wheel off the Cuda I'll measure things.
 
I have a B body rear if you are interested.It has stock axles and backing plates.It came out of a 69 roadrunner.Also have a 489 case posi with 4.11s. included are new spring perches. Mark
 
d5667 said:
Everyone has an opinion.This is another-coulda/woulda/shuuda.Anytime you start to frankenstein any type of vehicle you need to look to the end result and be realistic as to what you want out of the car.Regardless of what anyone says-you have picked the best all around rear for your car.It has held up to all the Chrysler engines-that in itsself is the best testimony available.Hindsight is 20/20 and that is what you are dealing with now.Buy new axles with the B body backspacing and use B body brakes-problem solved.Or you can do the same as one of the racers.He bought a Dana 80 from me and is going to cut it down.Anything is possible with enough time and money.Is a Dana really what you need? I doubt it.Again-you have the best all around rear for your car.You need to understand that bench racing-or bench building is relative to whom is talking.
Click to expand...

I didn't think he was talking dana ,just abody versus b body 8 3/4.........
 
Switching A body 8 3/4 rear brakes over to B body BBP will increase the overall width some.I can't tell you how much for sure but consider the width of the brake shoe difference
 
Swithing the backing plates don't in increase the overall width .If thet was so you would have to change the axles to also make up the differance.Depending on the depth of the backing plates will be the width of your brake shoe and drum.B bodys came with a lot of differant size brakes. Mark
dodge71demon said:
Switching A body 8 3/4 rear brakes over to B body BBP will increase the overall width some.I can't tell you how much for sure but consider the width of the brake shoe difference
Click to expand...
 
dartcuda1 said:
Swithing the backing plates don't in increase the overall width .If thet was so you would have to change the axles to also make up the differance.Depending on the depth of the backing plates will be the width of your brake shoe and drum.B bodys came with a lot of differant size brakes. Mark
Click to expand...

It's been awhile but I put 11" B body rear brakes on my Demon and ordered axles from Moser and all they wanted to know was what brakes I was using and they made the axles accordingly
 
i have a 70 Duster with a 67 b-body 8-3/4 and NO issues,I have 5 1/2 backspace on my wheels with 8in rims and have no problems,I put offset shackles on the rear but left front hangers stock--NO issues at all--- Steve
 
The axles would have been the same no matter what brakes you had.The backing plates make up the differance of what size brakes you have.I put 10 1/2 2" wide E body rear brakes on my barracuda The only thing that was changed was the backing plates.Of course new brakes and drums Mark
dodge71demon said:
It's been awhile but I put 11" B body rear brakes on my Demon and ordered axles from Moser and all they wanted to know was what brakes I was using and they made the axles accordingly
Click to expand...
 
..'68 - '70 B body rear axle is wider by 3/4" per side or 1 1/2" total.
the spring perches should be re welded accordingly,but the shade tree technique would be just install the springs as is,it can be done
..converting sm bolt to larger A body disc brakes will widen the the front track about an inch per side..no big deal but some don't like the way it looks.
 
The '73 up bbp spindles are 3/4" wider than the sbp spindles. They are b/e body parts installed on the a body.
 
One more time...a 66/67 B body 8 3/4 is a DROP IN for an A body.
No cutting, welding or drilling required.

The 68-70 housing is wider. The popular chart showing all 64-70 housings as the same is INCORRECT.

If you have a "29" body (Duster, Demon, 67-69 Barracuda, Sport), it will look BETTER than the factory.
If you have a "23" body (or 1st gen Barracuda), you will lose about 3/4 inch outside wheelwell clearance per side.

The disk brakes are what makes the front track wider on Dusters.

The 66/67 Axles puts the rears on nearly the same track as the disk front.

Your "29" body Cuda will be fine, shouldn't rub, and look great.

...and it's 3/4" per side at the perches. You can simply push, and it drops in.

I ran mine for years.

This has got to be the second best kept secret in the Mopar world!

This is what it looks like-
 

Attachments

  • Duster.jpg
    11.5 KB · Views: 415
Going from A body rear brakes to B body axle standoff/drums does increase the overall width of the axle. It increases the width about 3/8" per side or 3/4" in total.

The 66-67 rears are the best to find for the swap if possible. The perches are 44" on center instead of 43" so a little pull on the spring and it goes in. Done it many times. It's better to move the perch, but, sometimes you just don't have the resources.

Yeah that chart is a POS! :)
 
You must log in or register to reply here.
-

Back
Top