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Old 01-14-2004, 03:03 PM   #1
mister.freeze
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differentials

Anybody got any definitive answers on differential gear ratios? The Fox has 373 open diffs. My buddies Z71 has 343's. Would that be a good way to go for gas mileage? I'm running 33x12.5r15's, and want to go 35x14.50. Will I lose too much acceleration and torque? Also, gear vs lever vs air lockers: which is the least trouble? I'd really like TRUE 4x4 when locked w/out tearing anything up.
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'72 K5, known as 'the Fox.'
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Old 01-14-2004, 03:43 PM   #2
69k5
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go to www.4lo.com and put it in the gear calculator there. im assuming its a gasser. so anything in the 1800 - 2200 rpm range will get you the best gas mileage. probably will need the 3.73's with 35's especially if you want to pass someone.

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Old 01-14-2004, 04:15 PM   #3
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I've got 400hp, and being a stroker, plenty of torque. 9mpg just isn't cutting it at $1.46/gal.
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Old 01-14-2004, 05:38 PM   #4
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in that case numerically lower 3.42 3.08 would be more highway gears and mihght get you above 9 mph. gonna have to stay off the skinny pedal as hard as it is with a motor like that.
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Old 01-14-2004, 05:48 PM   #5
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OK. Now what type of diff? Gear lockers? Lever lockers? Air? Electric? Mini spools? I get stuck a lot because the Fox is heavy, the short wheelbase, and w/the xfer locked, I actually have a 2wd.
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Old 01-14-2004, 06:34 PM   #6
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in the rear i like detroits b/c they are almost indestructable. but they are also full time. if they do break or wear out you can rebuild one easy. they are also the cheapest locker you can get. in the front i would do something selectable so you can still turn. a locker in the front will inhibit turning quite a bit when its engaged. might want to just have a 3 wheeler. my personal preference is an ox locker but they are only made for a few axels. its selectable and done by a cable so no electronics, air or anything to mess up. just pull it and go. looks like an e brake handle. dont know anything about spools. you can always just weld up the rear.

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