I have 69 mustang 302, 3speed, with 9in rearend, whats the best performance gear?


New Member
Jul 9, 2004
I have a 69 mustang, mach1, 302, 3 speed transmission, with a 9in rearend. I 'm wanting to know what would be the best rearend gear to put that would give me good performance on long and short distance. If you could please e-mail me you advice at [email protected].

Thank a bunch,
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New Member
Jul 31, 2002
Fairfield, Ct
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rear Gears

I have an 8 inch trac-,oc with 3:55 gears. A little loud on highway for longer trips.

I just put in al aluminum driveshaft which helped immensley though.

My car is also a 66 though and is lighter.

If you plan on a lot of hiway driving 3:25 sound good

302 coupe

Founding Member
Mar 2, 2000
Macon, Ga.
A Mach 1 wouldn't have a 302/3 spd, and a 302/3spd car wouldn't have a 9". If the car is a real Mach 1(according to the VIN) it should be a 9". However, that would mean the engine and trans were downgraded sometime in the past. If the car is a regular sportsroof or coupe equipped with a 302, it should have a 8" rear.

Anyway, as for the gears, if you do much highway driving, go with 3.25's or 3.55's max. If most of your driving is in town, or below 55mph for sustained periods, you can use 3.70's up to 4.11's. The gears for 8" and 9" rears do not interchange, so be sure which one you have before you get new gears.