3.73 gears

Darkside

Registered User
Hey guys, there are some 8.8 in. rear end gears on Ebay that I'm interested in buying. They are Ford Motorsport gears out of a Mustang. Will they work in my 90 SC?
 
You won't want 3.73's in a 5spd car. 3.55's should be considered maximum if you intend primarily to drag race the car. For road manners 3.27's would be preferable.
 
Early vs. Late model 5-spd

Depends on which 5-spd you have. As you can see from the chart below, you can use a 4.10 gear with a late model 5-spd & have the same overall ratio as a 3.55 gear with an early model 5-spd. The Early model 5-spd has a 3.95 first gear. The Late model 5-spd has a 3.42 first gear.

4.10 gears x 3.95 = 16.1950

3.73 gears x 3.95 = 14.7335

3.55 gears x 3.95 = 14.0225

4.10 gears x 3.42 = 14.0220

3.27 gears x 3.95 = 12.9165

3.73 gears x 2.42 = 12.7566

3.08 gears x 3.95 = 12.1660

3.55 gears x 3.42 = 12.1410

3.27 gears x 3.42 = 11.1834

2.73 gears x 3.95 = 10.7835

3.08 gears x 3.42 = 10.5336

2.73 gears x 3.42 = 9.3366

68COUGAR
 
I thought first gear in the early model M5R2 was 3.75:1, not 3.95 ...

3.55 would be the most I'd suggest for a 5-speed car, pretty aggressive gearing.

And to answer the original question, yes, Mustang 8.8" gears will fit in an SC diff.


cheers
Ed Nicholson
SCCoO
 
I want to put in the 3.73's in my car while it is still an auto. I plan to buy my exhaust, bigger fuel pump, MAF, TB, and hopefully heads and cam before I start with the 5-speed swap so I can do all this stuff at once. Shouldn't take more than 7 or 8 hours right? Anyway, unitil then(maybe a year) I want to enjoy the car and give it a little more aggresive feel. I will definitely switch back to 3.27's when I install the 5-speed.
 
Doh!!!!! I stand Corrected!

I thought first gear in the early model M5R2 was 3.75:1, not 3.95 ...

Yeah, I flubbed the dub on that one! Some of the gears have changed positions using the correct 3.75 first gear ratio. Here is the Corrected gear vs. tranny list:

4.10 gears x 3.75 = 15.3750

4.10 gears x 3.42 = 14.0220

3.73 gears x 3.75 = 13.9875

3.55 gears x 3.75 = 13.3125

3.73 gears x 3.42 = 12.7566

3.27 gears x 3.75 = 12.2625

3.55 gears x 3.42 = 12.1410

3.08 gears x 3.75 = 11.5500

3.27 gears x 3.42 = 11.1834

3.08 gears x 3.42 = 10.5336

2.73 gears x 3.75 = 10.2375

2.73 gears x 3.42 = 9.3366

68COUGAR
 
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