To swap rears or swap gears??

Black1987Stang

Active Member
Aug 22, 2004
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Jersey Shore
I'm in need of some lower gears, mainly because of going turbo next year and something better than 2750 rpm at 70mph. I can get a complete 373 rear for 50 bucks. Question is would it be cheaper to have a shop put in the new gears in my existing rear or buy the rear, rebuild it myself and have the shop just swap the rear? I would just do the gears myself but it will be my daily driver and I don't have a garage to do it in this freezing weather.
 
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If your going to have a shop do the work, i woud say i'd just swap rear end gears. Mainly because around here a gear swap is $300.00 at a "Mustang shop" and probably less at any normal body shop. To swap rear ends i'd say it would take longer and the total bill would end up being more. And really you should be getting quotes from a shop and not asking us..... not to be a smart ass or anything, but were not the ones doing the labor.
 
drop the rear out put the other in..its manily 5 bolts and then springs...preety straight foward....get a torpedo heater...then things are amazing.
Yep, it's that easy. Piece of cake. :nonono: Don't worry about pulling the axles, diff, ring gear,driveshaft, pinion, then shimming the pinion, setting the backlash, checking the contact, etc. You also might as well change the wheel bearings and rebuild your trac loc too while you have it apart. If you have access to a dial indicator and some knowledge on how to use one you can do it yourself, but it can be pretty complicated if you don't really know or understand the general concept. Also, seing how you don't really have a place to do it, you should probably just have a shop do the work. Labor for just the gears would probably be about $300.

I'm in need of some lower gears, mainly because of going turbo next year and something better than 2750 rpm at 70mph. I can get a complete 373 rear for 50 bucks. Question is would it be cheaper to have a shop put in the new gears in my existing rear or buy the rear, rebuild it myself and have the shop just swap the rear? I would just do the gears myself but it will be my daily driver and I don't have a garage to do it in this freezing weather.
I'm a little confused here. Your sig says you have 3.73s, and you need to change gearing, but you're looking at another set of 3.73s? :scratch: 3.27s would be your best bet, that is the most commonly used turbo gear.
 
Yea sorry about that, the rear I'm getting has 373's also do I now but I would be putting in 2.73's...for highway mileage and to help build boost. And if I go this route, I would be changing all axle bearings, seals, maybe even put in a better carrier and axles if I find a deal on some. and most likely a stud girdle either way. The one mustang shop I know of, Wicked, has a labor rate of $80/hr and I believe 300-350 labor for gears. so I guess it's just how fast they can do the rear, with a lift it's cake..all it is is brake lines, control arms, driveshaft, e-brake cable, and shocks from what I remember....
 
Yep, it's that easy. Piece of cake. :nonono: Don't worry about pulling the axles, diff, ring gear,driveshaft, pinion, then shimming the pinion, setting the backlash, checking the contact, etc. You also might as well change the wheel bearings and rebuild your trac loc too while you have it apart. If you have access to a dial indicator and some knowledge on how to use one you can do it yourself, but it can be pretty complicated if you don't really know or understand the general concept. Also, seing how you don't really have a place to do it, you should probably just have a shop do the work. Labor for just the gears would probably be about $300.


I'm a little confused here. Your sig says you have 3.73s, and you need to change gearing, but you're looking at another set of 3.73s? :scratch: 3.27s would be your best bet, that is the most commonly used turbo gear.


thats what we did for the 86 GT..just swaped in a rebuilt rear that came with the car....4.10's rebuilt t-loc ect...it was easy..only problem we had was the upper controlling arm bolts didnt want to budge...

but if you talking about doing gears your self then hell no i woul never mess with them..to much crap to check id rather pay the $$$ and have that done right...gears that wine are very anoying
 
I don't think you want 2.73's. At least go for the 3.08's or 3.27's.

If you can find a rear end with the gears you want, I'd buy it, install a posi rebuild kit (definitely something you can do yourself indoors), put in new axle bearings if neccessary and be done with it. If you plan to be putting serious power through this rearend with sticky tires, you should be looking at a 31 spline carrier and aftermarket axles.

It would cost a fair amount of money to have a shop install and properly set up new gears in your existing rearend. With a new gearset, posi rebuild kit and labor, you have to be looking at around $500+ easily.

Just be sure the rearend you are getting is either factory, or was properly set up if gears were installed by somebody. It's easy to check for improper ring gear wear by pulling the diff cover and using marking compound.
 
3 27's at the very least, i would go with 3 55s being that its a good comprimise between mileage and power and they tend to be a good blower/ turbo gear. If my memory is right i believe the stick shift t bird turbo coupes had 3 55 gears and the auto cars had 373s. If ford thought 3 55s were good in a turbo car why not do it yourself?