Yeah, about 1990 (ish) the speedo broke, and i took it out to the GMC dealership and the guy had that off and said a new one would be $100+, but that he could put the cable straight to the transmission and it would work, but wouldn't be 100% correct, so that's what we did at the time.
I'd like to get it right, but don't have the original. If it's anything like my Jeeps, you kinda need the original one to get the right part # or you just have to guess. I don't want to guess if it's still a pricey part (which I'm sure it is).
I found this site
http://www.transmissioncenter.net/sp...n_______va.htm
"#54RA2. If your truck tires have been switched to larger tires or you just need to speed up your speedometer this one will correct your problem. This part will speed up your speedometer reading. Cost $62.00
Qty 123
Speed Up Rate Select the Correct %Speed Up 11%Speed Up 20%Speed Up 28%Speed Up 38%Speed Up 44%Speed Up 78%
Other ratios available on special order, allow 2 to 4 weeks. No refunds on special orders. The male side can be turned 180 degrees, just remove the 4 screws and turn. We can slow your speedometer down as much as 58% or speed it up as much as 200%. Cost $72.00"
Kinda thought if I can figure out how much the speedo is off I can have them make me one. Anyone used one of these from that website and if so, did it work ok?