jamieNerikas66stang

i have a 66 gt with a freshly built C4, i have new 3.55s in the rear with a posi....

what tooth gear do i need now,...

sorry i dont have time to search, trying to finish a big order up

jamieNerikas66stang

no one?

2+2GT

It's going to be difficult without knowing your rear tire size, and the number of teeth on the output shaft inside the transmission.

jamieNerikas66stang

235/40/18

and no idea what tooth trans,...its a stock rebuilt 66 C4 if that helps out of a A code convertible

groho

here ya go.... try this link. http://www.sccoa.com/faq/speedgr.html

it appears to be 22.6 teeth, which is about right. I believe I'm running a 21 or 22 with a 3.25 gear.

groho

years ago I had to take a newer tranny to a speedo shop to have it calibrated and certified for a speeding ticket. I recall the owner saying "the rule of thumb, for every add/subtraction of a tooth, is a 10% change in the speedo" so at 50 mph, a one tooth adjustment would change your speed 5 mph, but at 20 mph, its only a 2 mph difference. so far this basic principle has worked for me

groho

and remember, it's opposite of the speedo adjustment. . . more teeth slows the speedo down, and less teeth speeds the speedo up.