Another rear end question.

[Usudno]

I believe I have an understanding of what I need as far as a rear end goes. That being said, I was quoted $800 to rebuild an 8.8 with 3.55 trac lock with me supplying the axels. There is only 1 shop near me that will tackle this job. The others say that they order replacements from jasper or other parts houses. My options are as follows,

1. Buy a used sn95, pull the Axels and swap which seems easy enough, or a fox rear and swap axles and add brakes. This leaves me searching for the best gear ratio for my setup. I was thinking 3.55s but I don't believe that it was an option in mustangs. Which axle would suit my needs best?? The additional cost of brakes on the fox axle isn't all that troubling, I was thinking of getting cobra brakes either way. Rear end cost here would probably be around $400 plus axles so $650 total for a ball park for a used rear with a compromise in gearing selection. With the sn95 without a brake upgrade I'm at $1050, fox width I'm closer to $1450 with brakes

2. Junkyard rear end housing running $200 plus $250 for axles plus $800 installation of new traction lock and gears, as well as another$350-$400 for brakes I'm at about $1650 for a rebuild.

3. Go with MPS and a complete setup brakes and all for $1800

4. If money were no object grab the $2000 moser from factory five.

I guess my main question is.... which way would you go and if I go with a used rear end what year/gearing will best suit the mark4?


Thank you all for the wealth of knowledge and willingness to share your experiences. This truly is a great community!

[scottiec]

Hey there. Gearing will depend completely on use of the car, motor, and trans. It really is a personal preference. Personally, I plan on going with 3.55s for the 302 with heads and cam. Also, the t5 had different first gear ratios.

[Jeff Kleiner]

Go back to your earlier rear end thread and read my comments about gearing:

http://thefactoryfiveforum.com/showthread.php?22411-What-s-the-best-way-to-complete-the-complete-kit

You will not find anything steeper than 3.27 factory installed in a SN95 axle and those are rare; most are going to be 2.73 or 3.08. When I do live axle builds I pick up a '94-'98 GT rear for about $250, add NRC axles & brackets ($410), a gearset and new bearings & seals ($250) and Trac-Lok rebuild kit ($55). All in around a thousand bucks. If you are not able to do the rebuild/setup yourself add a couple hundred for labor to have a shop do it.

Good luck,
Jeff

[CraigS]

I would go w/ Jeff's recommendation. I believe you are planning a 302 so I'd go w/ the 355 or 331. You can save a little money by having a shop do just the gear install/setup and TracLoc rebuild and install. Then you can easily install the axles, brakes, cover, and oil.

[Usudno]

Engine choice has changed to a 351w. My problem with jeffs plan is I can't find anyone to do the work at a reasonable cost. There are only 2 people near me that will swap the gears. I have confidence I can rebuild the traction lock. Not so much on the gears. The price to rebuild the rear end with new traction lock new ring and pinion all seals and me supplying new axles was $800. That seems a far cry from $250. 3.55 is the way I would like to go.

[ryanmac]

If looking for most economical path, then reconsider your 17" by 10.5" wide rear wheel choice, and get a 8.8 from a 2003 or 2004 GT 5spd car. Stock ratio for a stick was 3.55 for 2003 & 2004 (3.27 for 99-02). This will get you 5 lugs, the ratio you want, and the correct brackets for rear discs from 99-04 GT for less than $600. Just change the rearend gear lube, sandblast and paint it!

http://thefactoryfiveforum.com/attachment.php?attachmentid=60391&d=1478098952

The trade off (there is always a trade off) will be that you will have to get the 17x9 rear wheels (most would run a rear tire width of 275) because the 99-04 rearends are wider.

[Gumball]

If you decide you'd like to go the rebuild / refresh route on a used rear end, but can't find a shop to do the work, there may be another route. Through my local car-guy community, I was introduced to a guy who works out of his barn doing rear end and transmission work for drag racers. After doing a little checking with his past customers, I was satisfied enough to let him do the work on mine. I provided all the parts, including the used rear end out of a '94 SVT Cobra, and he charged me $200 labor. He installed new bearings, seals, and clutch packs, along with new axles. He also cleaned the housing and removed some of the original brackets that I no longer needed.

Never hurts to ask around. If you don't have a circle of car-guys in your area, this is an ideal reason and time to start building one - afterall, that's a big part of what the FFR experience is all about!

[Usudno]

ryan mac. that seems like a good idea. My only problem is I will have to see if Factory five will do the 17x9s front and back with the promotion. I was looking forward to some 315's on back!

[Usudno]

So the good news is I found a rear end for $399 out of an 04 gt. I was told that the 3.55 only came in the mach1 and bullits. The gt came with 3.27. If that's the case I would think a 96-98 rear end would be a bit better being narrower.

[ryanmac]

Here's an ad for 2003/2004 8.8 rearend with 3.55 gears and rear brakes for $680 from MPS Auto Salvage in Georgia.

MPS Auto Salvage - 2003 Mustang Mach 1 rearend (http://www.ebay.com/itm/like/122200222691?lpid=82&chn=ps&ul_ref=http%253A%252F%252Frover.ebay.com%252Frover %252F1%252F711-117182-37290-0%252F2%253Fmtid%253D1588%2526kwid%253D1%2526crlp% 253D53601919689_324272%2526itemid%253D122200222691 %2526targetid%253D85485281289%2526rpc%253D0.00%252 6rpc_upld_id%253D999%2526device%253Dt%2526mpre%253 Dhttp%25253A%25252F%25252Fwww.ebay.com%25252Fulk%2 5252Fitm%25252Flike%25252F122200222691%25253Flpid% 25253D82%252526chn%25253Dps%2526adtype%253Dpla%252 6googleloc%253D9015657%2526poi%253D%2526campaignid %253D239125209%2526adgroupid%253D14978428809%2526r lsatarget%253Dpla-85485281289%2526gclid%253DCKnG5v-gi9ACFZM2gQodRv4Cgg%2526srcrot%253D711-117182-37290-0%2526rvr_id%253D1118351569075&ul_noapp=true)

[Usudno]

I appreciate the link. I got a quote for a standard gt axle for 399 shipped from prestige. I think I'm going to go that route and stick with the 3.27 gear ratio.

[2bking]

When you have completed your build, you will have $30,000+ in it. Sounds like for another $500 you could have had exactly what you wanted wheels, tires, and ratio. Sometimes penny pinching leads to bad choices.

[CraigS]

The 327 will be fine w/ a 351. Heck even a mild 351 is easily 400hp w/ similar torque. I had a 400hp 351 and a 308. 3 yrs ago I went to a 331 and really liked that. This spring I installed a mild 408 and still like the 331. Right now I am in the middle of an IRS upgrade and it will have a 315. I would have liked to stay w/ a 331 but couldn't find a donor. I suspect that the 315 will end up staying in the diff for a long time.

[edwardb]

When you have completed your build, you will have $30,000+ in it. Sounds like for another $500 you could have had exactly what you wanted wheels, tires, and ratio. Sometimes penny pinching leads to bad choices.

^^^ What he said. I know these forums have the reputation for spending other people's money (probably deserved) but don't make a decision you will regret later. Stick with your dream of what the car should be. I've had both 3.27 and 3.55 final drives. I prefer the 3.55. Have you considered doing the rear end work yourself? I did the work on my last build, and it's no harder than many other tasks required to build these cars. I studied a bunch and bought a video tutorial. Worked out fine. It can be challenging with the various shims and spacers, getting the gear mesh right, etc. But it's not that bad IMO.

[Usudno]

The 351w is my determining factor. I'm sure the 3.27 are plenty good. If not it wouldn't be the end of the world to drive it out to Lake Charles and have them swapped.