I'm not sure if this implies to your transmission but when I did my 700R4 I had the same problem. I was told by my local tranny shop that the speedometer gear would need to match with the gear on the imput shaft. Depending on the person who rebuilt your tranny, there may be more than one shaft for your tranny (it all depends on what tranny you have). I know that the 700R4 has about 3 shafts that I know, it depends on the car that you have or your needs (I beleive that the corvette has the short one). If your tranny mechanic had to replace it, the other shafts are similar to each other and could be easily confused. One of the shafts is very close to being the same as the other, I know that the location of one of the shafts, the gear is off-set. The only other reason could be a wrong choice of speedo-gears. Well, I hope you fix the problem and it was of some help.
'67 RS/SS Camaro, 350, 700R4.
[This message has been edited by crene67ss (edited 02-16-2003).]