Rear end swap

[falconsdart]

What type of rear ends could I swap my 7 1/4 for? Do they have to be a body rear ends or can I use other body type rear ends? I had a friend say I could use rear ends from a 5th ave or a diplomat, is that true? Sorry for so many questions just curious on what my options are to avoid buying a bigger rebuilt a body rear end. Thanks in advance guys.

 

[66340SEDAN]

What type of rear ends could I swap my 7 1/4 for? Do they have to be a body rear ends or can I use other body type rear ends? I had a friend say I could use rear ends from a 5th ave or a diplomat, is that true? Sorry for so many questions just curious on what my options are to avoid buying a bigger rebuilt a body rear end. Thanks in advance guys.

Yes, you can use those rear ends.....

 

[72bluNblu]

You can use any rear axle you want as long as you can get rims with the right backspace to keep the wheels in the wheel wells.

The 5th Ave's and Diplomats with have an 8 1/4 rear axle, which is a good rear axle for even moderately hot small blocks. But, it's over 2" wider overall than the rear axle in your car now. Which means you'll need about 1" more backspacing on your wheels if you want them to stay in the same spot in the wheel wells. If you want to keep your current wheels, you'd need to make sure you have about 1.5" from your tire to the quarter panel right now. If you do you can go the the F-body 8.25" rear and still have enough tire clearance. If you don't have that much, you'll probably need rims with more backspacing.

I have a 68-70 B body 8 3/4 in my Duster, it's 3" wider than a stock A-body 8 3/4. But I also have modern style rims that have 7" of backspace. And Dusters have wider wheel wells than Darts to begin with, so I had more room to work with.

 

[goldduster318]

With the narrow body dart, I think I'd suggest a 65-67 B-Body housing. Will be about 1 1/16" wider per side than your original axle. That should be something you can deal with.

 

[Bad Sport]

What type of rear ends could I swap my 7 1/4 for? Do they have to be a body rear ends or can I use other body type rear ends? I had a friend say I could use rear ends from a 5th ave or a diplomat, is that true? Sorry for so many questions just curious on what my options are to avoid buying a bigger rebuilt a body rear end. Thanks in advance guys.

With the narrow body dart, I think I'd suggest a 65-67 B-Body housing. Will be about 1 1/16" wider per side than your original axle. That should be something you can deal with.

This ^^^

I have a 74 Dart Sport as well, and I put a B body 8 3/4 rear in and it is perfect with 10 inch wide / 5 1/2 inch backspace wheels.

View attachment Paved Road Shot2.jpg


Here it is with that current setup.


All I did was go through the rear and upgrade to 3.55's and a suregrip, all new bearings and seals and moved the spring perches in to the 43 inch on center to fit tha A body spec. B's are 44" on center.

Some will say just to pull the springs out, and that will work, BUT IMO, it will add side pressure to your spring eye bolts etc. Think about it, Ma Mopar didn't do it that way, lol.

 

[Bad Sport]

Here is another shot, I zoomed it in a bit so you can see it better.

 

[72bluNblu]

With the narrow body dart, I think I'd suggest a 65-67 B-Body housing. Will be about 1 1/16" wider per side than your original axle. That should be something you can deal with.

That's pretty much exactly the same dimensions as the F-body 8.25. The 65-67 B body lists at 54.25" flange to flange, the F-body 8.25 is 54.34".

I'd rather have the 8 3/4 too, but the F body 8.25's are probably easier to come by in the wrecking yards.

 

[goldduster318]

That's pretty much exactly the same dimensions as the F-body 8.25. The 65-67 B body lists at 54.25" flange to flange, the F-body 8.25 is 54.34".

I'd rather have the 8 3/4 too, but the F body 8.25's are probably easier to come by in the wrecking yards.

Yeah depends on where they are. You would absolutely never find F-body anything in a wrecking yard here in Michigan. They are long gone.

My friend bought a complete 3.23 Sure-Grip 1965 B-body 8 3/4 for $400 out of the Craigslist here. I had to beg him to get his butt over there ASAP. Was a nice setup, despite the 741 case it had the clutch type sure-grip. Well, well worth it. A lot of people put Dana 60s in B-body builds (seems a lot of drag vehicles being built) so they're certainly out there. We have it in his brown 1971 Demon now.

 

[MopaR&D]

+1 on the b-body rear i put one in my duster (sig pic) out of a 1967 coronet but if you have a dart or other "rectangle" car you will need extra backspace and/or thinner wheels/tires to make it fit. I have 275/60-15s on 15x8 rallyes with 1/8" extra backspace over factory and i had to roll the fenders as they rubbed a hair over big bumps and with trunk loaded down. More backspace would work but then I would need different wheels.

As long as you don't have a brawny torque monster with a manual trans and slicks i think an 8 1/4 would be much easier and cheaper overall. Those also came in Jeep Cherokees (XJ) which are everywhere but i think they are a tad too wide out of that vehicle.

One last point i think those early pre-'66 rear ends have a goofy tapered axle shaft setup am i right guys?

 

[65 Dartman]

One last point i think those early pre-'66 rear ends have a goofy tapered axle shaft setup am i right guys?

Nope - 64 was the last year for that tapered axle set-up in a B Body. A's never had them and don't know about C's

 

[72bluNblu]

Yeah depends on where they are. You would absolutely never find F-body anything in a wrecking yard here in Michigan. They are long gone.

He's in California. Not sure what the wrecking yard situation is up in Eureka, but he's probably not all that far from Wildcat in Oregon.

The F/M/J bodies don't hit the yards around here as often as they used to, but they still show up on occasion. Heck, I've pulled parts from a couple of '71 Darts, a 74 Duster, a few different 5th Ave's and Diplomats, and a handful of C-bodies that have all hit PickNPull in the last couple of years. I pulled a C-body disk swap off of a '71 New Yorker just a couple weeks ago, UCA's, spindles and caliper brackets. It had an 8 3/4 too, but I've already got a few out of earlier C-bodies that are a bit narrower and more useful.

Here's a few of my finds in the local yards. All of these are from the last 3 years. I didn't even take pictures of the F/M/J's, the 3 C-bodies or the 1/2 ton trucks I pulled parts from. There was even a few I didn't go look at because I knew they were /6, drum, 7.25 cars from the descriptions, so this isn't everything. And all of these were within a 30 minute drive.

 

[falconsdart]

Yeah the junk yard here in eureka really is terrible, there literally isn't a car there that is older than the 90s. Seems anything worth value was picked a long time ago or the moment it shows up in the yard. I looked up wildcat in Oregon and found several places but none with just wildcat as the city name. What county is it in? It'd call for a nice road trip too.

 

[72bluNblu]

http://www.wildcatmopars.com/

46827 SE Wildcat Mountain Dr. Sandy, OR. 97055

 

[falconsdart]

Thank you!

 

[MopaR&D]

Looks like i gotta man up you guys are going out of state just to find a good junkyard, we have one in CO for old cars but it's 4 hours or so from where i live.