differential change

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10-22-2013, 05:13 PM

klr650goldwing

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differential change

If I change the 3:73 gearing on my 2004, f350 V10 4X4 to 4:30 or 4:56 what would the RPM be with each of those gears if I'm running stock tires?
Thanks.

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10-22-2013, 06:41 PM

dkf

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Stock tires, auto trans with TQ locked in OD.

4:30 @ 70mph : around 2275rpm
4.56 @ 70mph : around 2400rpm

http://www.grimmjeeper.com/gears.html

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10-23-2013, 06:47 PM

PROSTOCK

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Take your current RPM at any speed and multiply by 1.15 for 4.30's and 1.22 for the 4.56. It's a percent change.
Go 4.56, I just did 4.30's from 3.73 and am not impressed.

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