What speedo gear with a C-4 and 3.25's???

red302 · Jun 15, 2007

'68 C-4 trans, 3.25 rear gears, and a 26" tall tire.....What tooth speedometer gear do I need? Thanks for any help.

rbohm · Jun 15, 2007

by my calculations you need an 18 tooth driven gear. this assumes a standard 7 tooth drive gear.

diablopony · Jun 15, 2007

I have the exact same set up as you and the 18 tooth gear is pretty much right on. Be sure to get a new gear clip as well.

jb1dsl · Jun 16, 2007

would a 3.55's and the rest the same need an 18 also or something different

rbohm · Jun 16, 2007

jb1dsl said:
would a 3.55's and the rest the same need an 18 also or something different

you would need a 20 tooth driven gear.

red302 · Jun 16, 2007

Thanks for the replys. I'll try the 18 tooth.

68keyblr · Nov 10, 2007

Sorry to dig up an old thread, but what speedo gear do I need for 3.73's?

D.Hearne · Nov 11, 2007

Mustangs Unlimited has a chart or the equation to figure the gear you need.

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