LuckyGuy

Just put a Tremec 5 speed on my '66 L79 coupe. Love it. However, I've noticed that the odometer and trip odometer are both spinning quickly. They are turning in tandem at the same rate but appear to be clocking about 1.4 miles for each one mile I'm actually driving.

Any thoughts on what could be the cause of this?

Plasticman

Then I am assuming your speedo is off the by the same amount, and you need a speedometer gear change in the trans (or a ratio adapter in the speedometer trans output or cable).

plasticman

LuckyGuy

Yes the speedo is out but by a smaller margin (i.e. it reads about 75 mph when it should read 70 mph). I will try and install the "correct for 3.36" blue 20 tooth gear and see what happens.