I'm installing a aftermarket cruise control, speed sensor on driveshaft, need to know how many pulses per mile. If I know the ratio I can take the tire dia. multiply times 3.14 to get how far it travels in one revolution, then divide that into 5280' to get revolutions in a mile, then multiply that times the gear ratio.This should give me the number of revolutions the driveshaft (pulses) turns in a mile. Could anybody help me out, Thanks.