Since installing a t56 transmission in my 87 trans am gta the speedo is way off and totally inaccurate. Calculates the miles practically by the second.

I was under the understanding that the 87 pontiacs had a digital speedo and not an analog. what am i encountering here i am clueless..

Please help.

 

The T56 VSS uses a different (much faster) pulse rate than the 3rd gen speedos. You need a signal calibrator to fix it. Cyberdyne sells one, I think you can get it from Jeg's.

 

Man, there are so many misc. parts you have to buy to put one of those things in a 3rd gen.

 

Yeah there are, but for the .5:1 overdrive and the fact that it's a lot stronger than a T5 it's worth it.