79-98 Mustang rear end?

[Mrs L]

Can anyone help me identify this rear end?
My husband began modifying it and added a custom housing.
I believe it has all the "good stuff" inside that makes a car go faster and is lighter in weight.
Your help would be greatly appreciated!!
Can send other pics if needed.

 

[broncojunkie]

4-lug 8.8 rear end should be for a fox body. It's set up for drum brakes, which is another hint. Long studs is a performance upgrade...or at least, a modification required by most tracks. The aluminum cover acts as a stiffener to help keep the rear end together under hard launch. Can't tell what brand it is, but I recently purchased a Ford Racing one for $175. They're not exactly cheap. To be honest, most of the money will most likely be inside the unit. Gears, possibly upgraded carbon fiber clutches, maybe even an aftermarket carrier. Judging by the 4-lug axles, I would guess it's a standard 28-spline dif/axles. Hard to tell if the axles are aftermarket "forged" or just factory steel. They also make 31 spline axles in 4-lug. It would be nice to get a closer look...pop off the cover and maybe pull an axle, if they look like they're forged. Depending on upgrades, around here that rear end would bring $300 at an absolute minimum and around $600 depending on whether or not the axles are forged and the carrier inside is upgraded with an aftermarket or 31 spline unit of some sort. It would also be worth removing the cover to check the gear ratio. The ring gear will be stamped on the edge. With all the work he did to this, I'm betting it has a nice low gear, such as 3.73 or 4.11.

 

[Mrs L]

Thank you bronco junkie for your quick and detailed response! If I get someone to take off the aluminum cover and took some pictures - would that help you to know for certain what's inside? I just remember my husband telling me how lucky he was to find this axle and how much money he saved-opposed to buying a new one.

Sincerely,

Mrs L

 

[broncojunkie]

By pulling the cover, you can spin the axel (very easy to do) around until you can read the stamp on the edge of the ring gear. You'll most likely see a number like 327, 355, 373,410, 411, or 456. The higher the number, the lower the gear and probably more desirable to someone looking to buy a rear end. The upgraded/lower gear isn't very expensive in itself, but it's not easy to swap them, so people will usually pay more if the work has already been done. Also, a look inside will tell us if it has a stock-style or aftermarket carrier. It will be a little more difficult to find out if a stock-style 31-spline carrier is in it. The passenger car/mustang 8.8 rear ends had 28-spline carriers/axles. A popular upgrade is to pull a 31-spline stock carrier out of an explorer rear end and buy new aftermarket forged 31-spline axles to match. I don't have a lot of experience with this upgrade, but I figure it may be a little more difficult to check unless someone pulled an axle out. That's a good 30-minute job to take one out, check it, and put it back in.

But I can tell you that you need to pull the cover to check the ring gear ratio. If you sell the rear end, that's the first question someone will ask. Hope this helps!

 

[Mrs L]

Thank you so much for your help. I will definitely get some help to take the cover off and see what is inside!

 

[Mrs L]

By pulling the cover, you can spin the axel (very easy to do) around until you can read the stamp on the edge of the ring gear. You'll most likely see a number like 327, 355, 373,410, 411, or 456. The higher the number, the lower the gear and probably more desirable to someone looking to buy a rear end. The upgraded/lower gear isn't very expensive in itself, but it's not easy to swap them, so people will usually pay more if the work has already been done. Also, a look inside will tell us if it has a stock-style or aftermarket carrier. It will be a little more difficult to find out if a stock-style 31-spline carrier is in it. The passenger car/mustang 8.8 rear ends had 28-spline carriers/axles. A popular upgrade is to pull a 31-spline stock carrier out of an explorer rear end and buy new aftermarket forged 31-spline axles to match. I don't have a lot of experience with this upgrade, but I figure it may be a little more difficult to check unless someone pulled an axle out. That's a good 30-minute job to take one out, check it, and put it back in.

But I can tell you that you need to pull the cover to check the ring gear ratio. If you sell the rear end, that's the first question someone will ask. Hope this helps!

Hello Bronco Junkie,

I was finally able to get the cover off and it looks like the number on the gear is 373 and the maker is Ford? I took some pictures. By looking inside can you tell me more about the gear? Again - your insight and knowledge has been very valuable to me. I hope to start selling all the parts my husband bought. On the Axel 3 picture - it looks like my husband marked the gear. He would mark parts on occasion...don't know if it means anything.

Thanks again

Mrs. L

 

[broncojunkie]

I take it this rear end was built for the mustang I can see in the background? Judging by the taillights, I'm guessing 79-82? The older fox body cars are my favorite. They are awesome cars, but didn't make much power from factory specs. All of the earlier cars (even equipped with v8) had the smaller, weaker 7.5 rear end. A must-have upgrade for these was an 8.8 rear from a newer v8 mustang. The newer 4 cyl and 6 cyl cars also had the 7.5, so they needed the same upgrade when converting to v8.

So you're correct in thinking it is a performance rear end... although basically stock, for the most part, in the later v8 cars. All mustangs equipped with the v8 and 8.8 rear had 28-spline carriers/axles. I would presume this one is 28 spline, but I can't be 100% sure from the pics. Someone else may be able to chime in and know of a way to tell without pulling an axle out.

If it does have a 31-spline carrier and axles, I would value this rear at an additional $100-150.

The 3.73 is a great upgrade to an otherwise stock 8.8. Most consider it a perfect gear for street and track....at least, a good compromise for both duties.

As it sits, I would think a value between $300-500 would be reasonable. $200 for a stock rear and additional value for the upgraded gear, aluminum bushings, and aftermarket cover. Someone may be willing to pay a little more if it has a 31-spline upgrade. A $700 value would be pushing the limit, in my opinion, if it is 31 spline.

These prices are what I'm seeing in my area here on the east coast. Other markets might be a little different. From what I see, I wouldn't hesitate to give you $400 as it sits (presuming 28-spline). If it has 31-spline upgrade, I'd pay $550. These are real/actual values, as I am currently in the market for one (although not desperate for one right now, I'll need it by next year). That's important to note because numbers often get thrown around by people who aren't in the market. I know to build one like this, it would cost me in the neighborhood of $800. I would take a chance on someone else's work if I could save $2-300. Hope that makes sense!