well I have a 92 Camaro, so that's electric, and I swapped a mechanical t-5 in. I order this part http://tpiparts.net/inc/sdetail/7587 and hooked everything up, but the speedo still reads ~32mph (while car is not moving)and when moving (~30mph+) will jump to 60mph and kinda just dance between 30-60mph.

any ideas on why its doing this?