the speedometer on my car currently reads about 9-10mph slow suggesting i need go down a couple of teeth on the speedo gear. right now it has a 22 tooth in it and from what i figure i need to drop at least 3 teeth making it a 19 tooth. the lowest tooth count i have found is 20...can i get a 19? (Muncie Transmission)

The part number for a small diameter driven gear with 19T is 3987918. Check your 22T to find out if it is small(25/32) or large(7/8) diameter they made them in both sizes for the 22T driven gear. If its small just swap out your 22T for a 19T. If its large you will not be able to use that part number.

Depends on at what speed it's 9-10mph off. If you already know how many teeth are on the drive gear (the one on the tailshaft), go to http://tciauto.com/tech_info/speedo_gears.htm & there's a calculator to tell you how many teeth you need on the driven gear.

If you don't know the tooth count, or if you can't get it right with your current drive gear, go to novaresource.org with your tire diameter (calculator for that at the TCI site, also) & rear gear ratio, & you can figure out what speedo gear ratio you need, & what combos are available. TCI sells gears, but I get mine at the Chevy place. Muncies have 2 different diameters of drive gears, so you might need to go to www.dandltransmission.com (http://www.dandltransmission.com/muncie.html) for gears.

www.novaresource.org/speedo.htm (http://www.novaresource.org/speedo.htm)
www.novaresource.org/speedo2.htm (http://www.novaresource.org/speedo2.htm)