I do a cable drive mod to GM T56's that allows you to use both the VSS and a cable speedometer. I've been doing these for years now but haven't advertised much because the speedometer drive gear I use was discontinued, but just last week they became available again.

I modify your housing and include speedometer gears matched to your rear axle ratio and tire size. I've done a number of mods for people on here and over at ls1tech.

PM me for any questions you have.

Here is a thread started by one of my customers about my work.

https://www.thirdgen.org/forums/clas...xcellence.html

 

I've just got my web site up for my conversion. It's a work in progress

http://www.t56cablespeedometer.com/