Last year I decided to gut all of the factory wiring in my 90 iroc a bit in haste when I installed my FAST XFI. I had no speedo, but it really didn't bother me for ahwile. Since then I have went to a th400 and gear vendor. I decided to order for a 90 chevy 454ss, as it used a turbo 400 and vss. We decided to use the factory ecu as a vss buffer, since I could change the calibration in tunercat eventually. we hooked just the necessary pins. b9 and b10 go to the sensor, b11 goes to the cluster and we have power and ground. The problem is when the wheels are moving, the speedo is burried at top speed.

Are the speed sensors between vehicles different? The car has a 4.10 but that obviously shouldnt throw it off THAT much. I have tried searching but havent found this particular problem.