Im about to purchase a set of 4.10's for my 1996 mustang. I need to know if i need a speedometer gear or the speedcal for this year to correct my speedo?... and should i go with 3.90's or the 4.10's??...any opinions?? Thanks alot......
You MUST get the SpeedCal. Why? First, the speedo gear really only corrects up to 3.55's. 373s will be off and 410s even more so. The new gear doesn't mesh correctly with the gear drive unit and it will come apart in a few months and you will have no speedometer and the car will stall.
Get the SpeedCal. You need it. (Use your original speedo gear)
Finally, if you do not have to drive in snow and ice, go for the 4.10s.