i found the stock one i used to have in my car was pretty slow compared to the autometer one that i had in there. had them both in at the same time for a little bit. there was almost a 1000rpm lag in the stock one if you were revving 1st and second gear out when driving.

also need it for the CA so the induction loop probaby wont do the job

found a place that will put their own unit in the stock tacho and then calibrate it to suit