Thread: Posi Rear Ends
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Old 05-11-2009, 01:14 PM
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Location: American Fork, Ut
Cobra Make, Engine: 66 Cobra
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Rick, I have have not bought the gears yet but was thinking of the 3.50s, not based on overdrive fifth gear that is .68 to 1, but on 4th, that is 1-1.

With 3.5 at 60 mph 4th is 2713 rpms and 5th is 1844 rpms.
With 3.73 at 60mph 4th is 2892 rpms and 5th is 1966 rpms.
I believe that's right based on the calculation program I used.

I wasn't considering the overdrive factor as the basis for the math. I felt dropping it down to 4th was fine when the power was needed. Looking at the numbers again I may go with the 3.73s.

Wayne
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