Just about finished with the 85 Monte Carlo with an LT1 and 4L60e. I have all of the factory gauges working except for of course the speedometer. I have used the Abbott Cable X before, but it is a little pricey. I am curious if anyone has a cheaper alternative? I am sure there is something out there, I just have not ran across it yet.

I know it is an LT1, not my first choice but that is what the customer wanted....

 

I bought a adapter that lets you use a 700r4 tailshaft - it adds the mech speedo along with the electronic one, its about the same 300$ or so

 

I took the guts out of an autometer 3 and 3/8" electric speedo and shoved them behind my face, then put a decal over the face to change it to a 120mph speedo. Cost less than 75 when done. Of course you have to do a little grinding to the back of the plastic gauge cluster and I nailed an autometer on fleabay for $50, another user made me the gif for the overlay cause he was doing the same thing and had the photoshop talent to do it, so thats how it was so cheap.

 

I used a 700-R4 output shaft in my 4L60E when I rebuilt the transmission and a VSS tone wheel from Advance Adapters and this allowed me to use the cable speedometer in my '71 GMC. If you have to rebuild the transmission this would be the way to go, if the trans is good, than this would be a little pricey. I used an Abbot Cable X on one project and was not 100% happy with the results I received. There was another company out of Ann Arbor, MI that promised a great electronic speedometer drive, but was not able to deliver any results. Unfortunately, there are no cheaper alternatives when it comes to this swap!!! Hope this helps!!!

Mike

 

i was think something like this. i think its the best bet to get it acurate.
what did it run you for the vss wheel? did it come with a tail housing?
gabriel

 

I recently bought the cable x box and sent them a email before i bought it concerning the problems i heard about the unit. They sold me a 30 slot unit which is more accurate and does bounce around. I could not be happier with this unit, my speedo is smooth and have had no problems with it. I bought it off ebay which i believe is straight through them and i got it cheaper. I wanted to keep the stock speedo so for me this was a great unit. When you hook it up you have to go straight to the speed sensor off the trans, not to the computer. Its a great option if you want to keep your stock gauges.

 

I was able to get this one smoothed out but keep the bends in the cable smooth.