73 Dart Rear End Swap

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DartVadar

DartVadar

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So I've come across a bit of a set back, well not really, I just have to find another A-body 8.75 rear end. I was going to use what I thought was an 8.75 in an old Cuda, but because it was in the grass it couldn't see it was actually a little 7.25.

The plan was to put that in with my new 360, as I don't think my current 7.25 will be very happy with close to 400 Hp going to it! LOL

I think my grandpa has a housing for an A-body sitting around somewhere so I might just buy a center section, axle shafts etc... But I was wondering what kinda gears I should get, I've got a Comp 268 cam and still deciding on a converter (Probably a 2000 stall) and tire size. What combo of tires and rear gears would be good for a combination of street and strip? I was thinking 3.55s. Fast acceleration is kinda what I'm going for.

And on a side note if I did install the 360 and run it with the 7.25 rear end how long do you think It would last before it blows? What is the maximum power they are rated for? LOL
 
If you babied it like roll out at idle before easing into the throttle you probably would be surprise how long it would last. If you got out on road and romped on it expect to call a tow truck or your buddy with a trailer.
 
Find a rear from a c body or other big bolt pattern car and have it narrowed, about $150 - 200 to narrow the housing. It will probably already have big bolt pattern brakes. Spend another $300 or so and buy good axles and you're done. For what they're asking these days for small bolt pattern A body rears I'd do this.
 
You don't have a ton of cam, so I think with a 2000/2500 converter, and some good tuning, a 3.55 will be just about right.

Hopefully Grandpa's housing will work out for you.....It would be nice to move up to the 8.75 and be done with it. :D
 
My grandpa also has another 8.75 that is out of an E-Body (old mopar guy with ALOT or parts!) only problem is it has 3.23 or something and it's open diff I'm pretty sure, still heaps better than what I've got. I was hoping not to have to shorten it but if it's so cheap I may as well just do that and then I'll have brakes that work and everything. I'm going to rummage around and see if he doesn't need some stuff. He has an entire sea-can full of cuda parts, shells, and a reinforced ford 9 or something, and ANOTHER 8.75, I probably have the available parts to put together a rear once it's shortened.
 
Find a rear from a c body or other big bolt pattern car and have it narrowed, about $150 - 200 to narrow the housing. It will probably already have big bolt pattern brakes. Spend another $300 or so and buy good axles and you're done. For what they're asking these days for small bolt pattern A body rears I'd do this.

The C and E body rears are much wider. The cheapest option is to use the 65-70 B body rear in your A body. It's only about and 1 1/2 -1 3/4 inches wider on each side (the 65-67 is even slightly more narrow). They can be had whole for $100-$250.

The A body spring seats are 43 inches center to center and the B body is 44 inches. Some people move the seats in a half inch, I just pull the leaf springs sideways and the rear bolts in place.

The 73-76 A bodies also had a wider track on the front with the disc brakes and a narrower track on the rear. The B body will fix that and give you the same footprint front and back.

Also, if you want to be REALLY cheap, the A body 8 1/4 (one quarter) rear (available in bbp) is a bolt in swap and it holds up to a lot more punishment than the 7 1/4.
 
gregpurcell said:
Find a rear from a c body or other big bolt pattern car and have it narrowed, about $150 - 200 to narrow the housing. It will probably already have big bolt pattern brakes. Spend another $300 or so and buy good axles and you're done. For what they're asking these days for small bolt pattern A body rears I'd do this.

The C and E body rears are much wider. The cheapest option is to use the 65-70 B body rear in your A body. It's only about and 1 1/2 -1 3/4 inches wider on each side (the 65-67 is even slightly more narrow). They can be had whole for $100-$250.

The A body spring seats are 43 inches center to center and the B body is 44 inches. Some people move the seats in a half inch, I just pull the leaf springs sideways and the rear bolts in place.

The 73-76 A bodies also had a wider track on the front with the disc brakes and a narrower track on the rear. The B body will fix that and give you the same footprint front and back.

Also, if you want to be REALLY cheap, the A body 8 1/4 (one quarter) rear (available in bbp) is a bolt in swap and it holds up to a lot more punishment than the 7 1/4.
Click to expand...

But wouldn't putting a b-body rear in as is limit tire width? Right now the max I can fit is about 245s in the rear, would like ateast that or even a bit wider with the new rear end.

And I was looking Into 8.25 swaps but I'm having trouble finding them near me, I can easily get a Dakota 8.25 but that's a bit different.

Would an a body 8.75 fit in if the spring seats are moved in a bit? And just run a different offset tire to fit?
 
The A body 8.75 is a bolt in swap. The spring seats are the same (43 inches ctr to ctr) as 7.25 and 8.25 A body from the early 60s to 76. The two big problems with an a body 8.75 swap are:
#1. They are VERY PRICEY and
#2. Most a body 8.75s have the 4 inch (small) bolt pattern and when putting one in a 73-76 you have to deal with the conversion to BBP axles/backing plates/drums. (making it even MORE expensive)

The "different offset" wheels are what you want with the B body 8.75 swap. The drums sit further out and if you use negave offset wheels you have more room toward the inside before it hits the leaf spring. It's possible to order wheels with the correct offset for the new rear. Most people report less problems with wheel clearance on the later A bodies which have large open wheelwells. The late 60's Darts had more problems.
 
DartVadar said:
But wouldn't putting a b-body rear in as is limit tire width? Right now the max I can fit is about 245s in the rear, would like ateast that or even a bit wider with the new rear end.

And I was looking Into 8.25 swaps but I'm having trouble finding them near me, I can easily get a Dakota 8.25 but that's a bit different.

Would an a body 8.75 fit in if the spring seats are moved in a bit? And just run a different offset tire to fit?
Click to expand...

8.25s are very plentiful. Just gotta know where to look. Most junkyards will have a couple. Heck watch the classifieds here, you may just find one near you in there.
 
dukeboy_318 said:
8.25s are very plentiful. Just gotta know where to look. Most junkyards will have a couple. Heck watch the classifieds here, you may just find one near you in there.
Click to expand...

I'm starting to like the idea of an 8.25. But how much abuse could they take? Could I have issues with it if I took it out to the track with a set of slicks on the rear?
 
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