You can....change the drive gear on the output shaft of the transmission along with the driven gear the the speedometer cable slides into for less than $10 or so. Google is your friend on the specifics. A couple years ago I did the research and had the necessary info at ready recall for about....Oh, 10 minutes. However with 4.10 rear gears (stock was 4.57) and a .72 5th gear T5 the speedometer in my 51, 3600 is pretty much accurate with the appropriate speedometer drive gears installed in the T5.
Lugnutz may step up and provide specifics, he is the Man on these issues.
Good Luck, Ron
