Thread: 55.2-59 speedo question
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Old 07-16-2020, 12:29 AM   #3
mr48chev
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Location: Toppenish, WA
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Re: speedo question

You have to have a cable housing that matches both the speedometer and transmission speedometer drive housing. As long as the transmission has the right piece to drive a speedometer cable.

It's just a parts house item if you don't have one. The main issue with cables is at the speedometer rather than the trans. later cables got away from the nut on the end of the cable that screws on the speedometer and has the push on end held on by a tab on the speedometer.

This is saying that the same speedometer cable will work from 37 to 72 https://www.classicparts.com/1939-72...ctinfo/24-574/ Including automatics. It might be a tad short for a 350 trans swapped into a TF though.

Parts houses also an extension cable that is about 15 inches long to use on Chevy trucks that need a longer cable.

You still have to figure out your tire height and rear axle gear ratio to calibrate the speedometer.
Or cheat and take the truck for a drive and use a GPS to check the speedometer at a set speed like 60 and figure the percentage it is off and then adjust the drive and driven gears in the trans to correct it.
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Last edited by mr48chev; 07-16-2020 at 12:38 AM.
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