i picked up a getrag out of a late 1990 one ton 4x4, got it all together and running. but my speedo is 5 mph faster than my actual speed.
so say it says 40, im actually doing 35.
do i need to go get the little gear box dealy worked on by my speedo shop to make this work right?

otherwise this is one hell of a good set up, now that i got it together.

 

oops sorry forgot to mention this is a 93 w250 truck that i put this pile all into

 

You probably have the wrong speedo gear in there they make a few different ones. It all depends on your rear gears and tire size as to what gear you need.

 

ah, got ya.
i should be able to get away with swapping the gear from my auto 205 into the manual 205 then.

after looking at the parts manual i see how this works.
same as the fords i grew up working on....

 

If the speedo cable hooked up the same, then it should be a direct swap. My NV4500 reads about the same, 5-7mph faster then actual speed. I haven't opened it up to look at the gear yet, but obviously it's geared for a 4:10 axle, not a 3:54.

 

My speedometer reads 5-7 MPH faster than my GPS. My odometer reads exactly spot on. Chrysler engineering at its finest!

 

yep, speedo gear it was. 14 teeth vs 16 teeth.
all is good now... or as good as it will get.
now off to the cruise control.
i dont use it much, but i like to have it sometimes

 

I'm betting your odometer is off now. Check it with a GPS.

 

close enough for me.
i will check it when i get to go on a trip... but that will be a while.
this is my play toy now and i dont drive it much. yesterday was the first time i have drivin it in a month, after tearing the center out of my flexplate...
i still need to get my rear driveshaft back from the shop, the guy who does the work went on vacation. it will be done monday though, and i will probably pick it up then or tuesday.