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Old 01-12-2017, 01:50 PM
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Bill Hanlon Bill Hanlon is offline
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Join Date: Feb 2005
Location: Fredericksburg, TX
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3.23:1 is likely, but it is easy to compute rear end ratio (assuming no posi-track which I don't think was available in 56) by:

1. putting ONE side of the rear axle on a jack stand to get ONE rear tire off the ground
2. put a chalk mark at the bottom of that tire
3. put a chalk mark at the bottom of the driveshaft
4. put the transmission in neutral and release the parking brake
5. have someone turn the marked tire exactly 1/2 rotation while you count rotations of the driveshaft
6. the number of driveshaft rotations is your rear end ratio.

If it is just over 3 revolutions, it'll be a 3.08
If it is about 3 1/4 revolutions, it'll be a 3.23
Just under 3 revolutions is likely a 2.87

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