7 or 8 Tooth Speedo Drive Gear??

Did some '96-'98 T45's in Cobra's come with 7 tooth drive gears instead of the normal 8 tooth drive gear? If all other factors are the same, how much would a speedo differ if a tranny had a 7 tooth from an 8 tooth gear?

I put a '96 Cobra tranny in my '98 GTand my car is showing 1 mile on the trip odometer at almost exactly the sme time I pass a 9/10 mile marker. So I am wondering if my '96 tranny might have a 7 tooth speedo gear since the's odometer is reading faster than the car is actually traveling.

Anyone have any thoughts on this?

That will make life a lot easier if I go through with the gear swap.

RandyStinchcomb said:

....... as a "rule-of-thumb" each tooth is worth @9 mph

Click to expand...

Do you know at what speed this would be? 1 tooth difference would have to be X percent off. If it's off by 9 mph at 100 mph,then that's 9% off. Which would confirm my theory of getting 1 mile on the odometer at the 9/10 of a mile, mile marker.

Which I am inclined to think is true at this point.