[dawg]

if you math wizards can check my math for correct speedo gearing
27.1 inch diameter tire
tire revs per mile 768.0
3:73 rear ratio
speedometer calibrated at 1000 revs per mile.
I come up with a 7 tooth drive gear (on tranny shaft)
20 tooth driven gear (on speedo cable)
that will give a .50% margin of error.
Id rather the speedo read a bit high than low.

[jimfulco]

8 driving 22 will get you closer.

http://novaresource.org/speedo.htm