I just swapped in a 3:42 posi in the place of my 3:08 peg-leg. I was wondering if there is any way to correct the speedo without a new prom. I want to be able to check my mileage with this new rear ratio, but can't because of this. Thanks guys.

 

You have to swap speedo gears on the transmission.

There is a website that can tell you which gears you need based on your tiresize, etc. but I can't remember the location of it.

 

I don't believe my tranny has speedo gears, sinse it has no speedometer cable. It has an electronic speed sensor where the cable would usually go.

 

still gear driven.....700r4 or T-5?

 

It still has speedometer gears inside the tranny that send pulses to your ECM. goto www.700r4.com (not right now though, the server is down for a bit), click on Useful Tools, then Speedometer gear calculator. This will tell you which gears you need to purchase to make your speedometer work correctly. Do some searching on this board and you'll find a great article about the different gear combos. There's also a tech article on this site (https://www.thirdgen.org/newdesign/t...eedogear.shtml) that tells you wnat needs to be done to swap the gears. Good luck!