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Discussion Starter · #1 ·
I know the potential for cutting down (narrowing) 8.8’s as an ‘affordable’ replacement has been kicked around before but upon searching the archive, I couldn’t find where anyone has successfully done it. With a little help from the collective, I like to do some R&D just to see if it might work.

Here’s my first question – Does anyone know where I can find a list of stock axle lengths? As an example, the short side (left) of an Explorer is about 26½” while the right is about 29½“. I’d guess some of the LTD and Mercury’s are in the mid-thirties.

Again, just some idle thoughts for a Monday afternoon so feel free to jump in! ::
 

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I haven't priced it, but - by the time it's all said and done - I'd bet you could get a Jag/Cobra rear end into a 'Stang for not much more than an 8.8 system - and you'd have a true performance IRS, not the rather crude FoMoCo one.

I suppose if you start with a wrecking yard donor, accept its condition as-is, and are equipped to do the heavy reworking and fab, there would be no comparison. But if you pay a higher price for a good core, rebuild it, and pay to have the fab done... betcha it's in the same ballpark.
 

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I know this doesn't answer the 8.8 install question but i think it would be far cheaper to have the 8 inch housing converted into a 9 inch housing. In doing so you keep your stock brakes and axles leaving only a third member to buy.
 

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the attraction is, with an Explorer 8.8, they are cheap and available (usually 250-400 in a junqueyard) you get the 8.8 rear (somewhere between an 8" and a 9" in strength), a favorable ratio (most are 3.73 or 4.10), and disc brakes already there. The issues are welding in spring perches, driveshaft differences, width, etc.....

biggest ill with a 8 or 9" is the cost of a Trac-Loc chunk :p Its as much as the entire 8.8" axle assy, unless you luck upon one cheap. I have a 9" housing and axles ready to go, but haven't decided if Im going to pony up for a LSD chunk. My wallet hurts right now ::
 

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I know this doesn't answer your question, but I think the reason you haven't found anyone that has successfully done this swap is the cost. I've done a little research on this topic myself and what I've found is I could put together a stock replacement type 9" for about the same or even a little less than modifying an 8.8 to fit. Assuming you take a junkyard 8.8 as-is, you still have to pay for cutting the housing and welding on new ends. If you do this you might as well have 9" housing ends put on to eliminate the c-clips and make axle selection a bit easier (9" axles are relatively cheap to order in any length you need). Adding it all up you have the cost of a complete 8.8 rear ($400-$800 depending on condition, ratio, posi or not, etc. Also, the cheap Explorer rears won't work, the pinion flange doesn't line up with the trans yoke in a Mustang so you have to get a wider rear to cut it to fit), new or reman axles made to fit (approx $300), plus labor for cutting the housing, rewelding the ends and replacing the spring pads ($250-$500). As you can see, you can easily spend over $1000 on this project and that doesn't include anything for the diff and assumes reusing your factory drum brakes. If you need to rebuild anything or change the ring & pinion it will cost you considerably more. While a race prepped 9" can cost well over $2000, a streetable rear can be put together for under $1000 using a bolt in oem 9" housing. With the exception of 65-66 original oem housings, 9" housing are inexpensive and not hard to find (my '71 housing cost only $50 bare). Center chunks can still be found reasonably priced in salvage yards (pre-'84 F150 trucks and vans are a good source). Unless you're given a usable rear for free it's just easier and no more costly to go with a 9". Even assuming equal cost for both rears, the 9" is still a stronger rear with better aftermarket support and parts availability. The 8.8 is strong enough for most streetable engines, plus it is a little lighter and more efficient (by 1 or 2 %) than the 9" so an argument can be made for doing the swap but it would depend on how much you're willing to pay to have those minor improvements in exchange for the 9" strength.
 

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Discussion Starter · #7 ·
Thanks for the StangNet heads-up. It was interesting reading and has peaked my interest to the point of beginning to looking for a machine shop and getting some quotes. ::
 

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Discussion Starter · #9 ·
I agree with your analogy Rickmaan and that’s probably why no one has done it. In my case though, I have the Explorer 8.8 with disc, 3.73's, traction-loc and only 30K of use lying in the back of the shop. Unfortunately, the pinon offset has really spooked me so I’ve begun this quest in hopes of still using it. Obviously, if someone steers me to a stock axle that’s about 28” in length, I’d buy two and modify the housing to fit them. ::
 

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the attraction is, with an Explorer 8.8, they are cheap and available (usually 250-400 in a junqueyard)

Not trying to heckle.....ya just gotta shop around.....

I have about 450-475 in my correct width 3.25 t-lok 9"
 

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I agree with your analogy Rickmaan and that’s probably why no one has done it. In my case though, I have the Explorer 8.8 with disc, 3.73's, traction-loc and only 30K of use lying in the back of the shop. Unfortunately, the pinon offset has really spooked me so I’ve begun this quest in hopes of still using it. Obviously, if someone steers me to a stock axle that’s about 28” in length, I’d buy two and modify the housing to fit them. ::
New axles made to what ever length you want are $300 from Moser. Moser
 

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Discussion Starter · #12 ·
By golly Gatorac, you may have something there! I knew Strange offer customs but I recall they wanted a lot more for theirs. I’ll contact Moser tomorrow and get a firm quote. :D
 

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Check your PM! Pics and discussion await!
 

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I don't know if anyone has actually done it but there's some really good info, including price quotes from Moser on doing the work, here.

I'm seriously considering doing this if I can find the parts cheap enough but that is a long way off.
 
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