I thought I would post some information I found while searching for a way to make my stock manual speedometer work with my new T-56 transmission. There are a couple of solutions available. There is a company called Abott Enterprises that makes a "black box" called Cable-X that will convert the signal received from the VSS to a manually driven speedometer cable. This solution costs aroung ~$300. I found another company that machines the T-56 tailhousing to accept a drive/driven gear while keeping the VSS stuff in tact. The company is called SouthWest Streetworks. Below is a link to their web site:

http://www.southweststreetworks.com/housing.html

I spoke with the owner of SWSW, a gentleman named Doug Smith, about converting my tail housing. He basically built a jig for his bridgeport to do these conversions. I'm running a G-Force 6 speed that was built from a new Viper T-56 core. The Viper has a large 30 spline output shaft (as opposed to the Camaro, Firebird, Mustang transmission). Doug has done quite a few of these tail housing conversions for Camaros, but hasn't done one for a Viper style tail housing yet. He said if I would send him my housing and output shaft he would convert mine for $500.

Not wanting to completely disassemble my new tranmission to send him the output shaft, I put a call in to G-force to see if they could "lend" me an output shaft. I spoke with Mark Wolfe at G-force and he was happy to send me a shaft to use. I can't say enough about the guys at G-force. They have excellent customer support and products. G-force is shipping the output shaft to me today and I should have it early next week. Then I'll forward the shaft and my tail housing to SWSW for the conversion.

The Cable-X box might be a fine solution, but I wasn't interested in that solution as I didn't want to have to find room to mount the box under the dash (already crowded with EFI, MSD6AL, coil, wiring, etc...) and deal with another electrical device. I'm hoping the tail housing modification will provide a better long term solution for me albeit a little more expensive.

At any rate, I wanted to share this information with TC in case any one else is contemplating a conversion and looking for an alternative to the Cable-X solution. Now if only the '66 Chevelles would have came with a 160 speedo like the vettes :D

I'll try and post some pictures when I get the housing back.

Thanks Ken, I'll be watching for an update as I'm not to interested in the add-on box either.

Did he happen to quote a price to you for the F-car T56?

I may be thinking outside of the box here, but is it possible to have the original speedometer converted? Maybe cannibalize the instrument cluster from a S-10 or Camaro? I guess you would still need an intermediate electronic controller of some kind between the trans and the speedo.

Dave

Thanks Ken, I'll be watching for an update as I'm not to interested in the add-on box either.

Did he happen to quote a price to you for the F-car T56?

I think he charges $495 for a standard T-56. As mentioned, a bit pricey, but to me a better long term solution. I'm not sure how long those black boxes would last. I've also heard that the speedometer cable bounces up to 25-30 mph when using one of those boxes. Take it with a grain of salt FWIW....

My D&D Viper T56 came with mechanical cable receptical already in the tailshaft and it did not require any relocation of my stock speedo cable. All I did was attached the gear and cable that had always been on the car and that was it. Perhaps D&D could shed some light on what they do to accomplish this and avoid all electronic stuff on this trans for us A-Bodied folks.

Here's another place that offers the conversion

http://www.jagsthatrun.com/

Here's another place that offers the conversion

http://www.jagsthatrun.com/

They no longer do those conversions, FYI.

My D&D Viper T56 came with mechanical cable receptical already in the tailshaft and it did not require any relocation of my stock speedo cable. All I did was attached the gear and cable that had always been on the car and that was it. Perhaps D&D could shed some light on what they do to accomplish this and avoid all electronic stuff on this trans for us A-Bodied folks.

D&D won't convert the tail housing unless you're buying the whole transmission from them.