my bad on the ticket deal, I saw speedometer and ticket and put the 2 together.
I understand the gear ratio bit as I am putting a 95 lt1 into an 80 elcamino so trying to get the manual speedo to the electronic tranny is fun.

for the sppedo calibration try http://www.abbott-tach.com/era.htm thsi way if you chang any of the components in the future ( tires, axles, etc,) your covered