speedometer gear

[john davis]

I currantly have a 700r4 trans with 3.70 gears with 245/60/15 tires in my 75 vette. My speedometer reads way too fast howmany tooth gear do I ned I have a 45 tooth gear now would a 42 or 43 be about right? thanks jd

 

[ssvett]

JD, I have installed many 700R4's in early model Corvettes, I ask my freindly GM parts man and he hasn't messed up yet. I know he will need to know the rear diff ratio and the hieght of the rear tires. Hope this helps............Steve

 

[Tom Bryant]

gear

John,
Steve is right. Your GM dealer has charts for gear selection. Also if your speedo is reading faster that you are going you need a bigger gear to slow the shaft down.
Tom