1964 Barracuda rear diff question

[jefo65]

I'm about ready to start wrenching on my 1964 Cuda project,..."A" body stuff is all pretty new to me, so get ready for the bucket of questions I'm sure to ask.
I want to get it as a rolling chassis first, so out with the old, in with the new. I want at least an 8 3/4 rear differential and was wondering if there's a bolt in application (housing and tubes) sold new or what models of past can I search that will get me as close to bolt in as possible.
As the project moves forward I'll start listing everything that comes off in the appropriate classified sections. Definately won't be bringing back to factory original so, interior, 273 motor, trans etc,...are going down the road.

 

[cosgig]

Alright Jefo, welcome to FABO, glad to have you with us!!

As for your 8 3/4" search, you only need look as far as any A body car from 1965-72! Barracuda, Duster, Dart, Demon, Scamp, any of these models could've come with an 8 3/4" that would be a straight bolt in! There is only one stock application for an A body, so it would originally come with the small bolt circle 4" lug spacing, which limits your rim choices, but matches your 64's original bolt circle!

If you're planning on upgrading to disc brakes in the front, and the larger 4.5" lug circle, that can be accomplished by using 1973 and later A body disc brakes, which already have the larger lug circle! then your rear end and rim choices open up and you need to find yourself a B body 8 3/4" from a 1965-67! They are only 1 1/2" wider than the A body units, and they already have the 4.5" lug circle!

The parts you need are all here somewhere, what you need is a specific plan of attack to build your shopping list around!! There are dozens of threads here of members and their combos to help guide you towards your goal! Questions asked here are always answered quickly and most all members are very helpful, so get your ideas together and join in the fun!! Geof

 

[jefo65]

Definately want the 5 lug 4.5" spacing front and rear,...so if I'm understanding ya correctly a "B" body diff is slightly longer but should bolt in? That would be good news!

 

[mguner]

It won't "bolt in" you will have to cut the welds on the spring feet and move them in about 1/2" on each side...

 

[65 Dartman]

Definately want the 5 lug 4.5" spacing front and rear,...so if I'm understanding ya correctly a "B" body diff is slightly longer but should bolt in? That would be good news!

Or find an A Body 8.75 and order a set of LBP axles from Moser. Scrounge up a set of LBP B/C/E backing plates and drums (10 or 11 inch) and it's all still a bolt-in.

 

[AJ/FormS]

Ive never tried it, but Ive had examples of all the As, and IIRC it would be pretty tough to stuff a 66 rear between those drop-down rear quarters skins and not have to get some special offset wheels. Now if youre in to the tuner scene, a mondo huge back-space might be for you. For me,not so much. They look good under a Demon though.

 

[jefo65]

Drop down 1/4's are getting "rounded"out...not a fan of the squared look and actually want a little tire sticking out.

 

[66fs]

Bolt in would also be an 8 1/4 from 73 to 76 A Body, Dart, Duster, Valiant. They have the 5 x 4.50 bolt pattern. It is also the right length. All rear swaps will require a shortened and balanced driveshaft unless you can find one from a Duster or A body Barracuda with an 8 3/4 or 8 1/4.

 

[AJ/FormS]

Well if the 1/4s are not going to interfere,and you actually want the wheels to stick out a bit, then the 66Bs might be just the thing for you, especially if you get one with the right gear-ratio.Guys have bolted them into Dusters and such.If youre not committed to any specific wheels yet,then I would certainly give it a try.Whats the worst that could happen?
-Yes the flange to flange is wider and the spring perches are out a bit.But theyre usually cheap. And unless the spring center to center is different than Dusters, then they will actually bolt on;with the correct U-bolts and shock mounts.
-Post the pics when youre done, please.
-And like 66 said, the 8.25 Darts fit. And on the street they can take a heck of a beating. You probably know that The early Dakotas had that size of diff. EFI Daks came with 230 hp-318s. As if that says much.
-What ever you decide,best of luck to you.

 

[pishta]

At least an 8.75...no, its at least an 8.25! They are cheaper, fit off a newer A and are plenty strong as well as having the bbp lugs. Come in SG and open. All Will require shortened drive shaft too.

 

[jefo65]

-And like 66 said, the 8.25 Darts fit. And on the street they can take a heck of a beating. You probably know that The early Dakotas had that size of diff. EFI Daks came with 230 hp-318s. As if that says much.
-What ever you decide,best of luck to you.

I did not know that about the Dakotas,.....definately an option I'll take a peek at.