Speedometer gears for 3.54 rear ratio- C4
 

I have a 1991 that is stock ( 275/40 ZR 17 stock tires ) and I installed a 3.54 ring and pinion. I am trying to find out the two speedo gears inside my 700R4. Can anyone help with GM part #'s or tooth counts? Thanks!! :chevy

Re: Speedometer gears for 3.54 rear ratio- C4 (Vettelover8360)
 

What ratio did you have previously?

Re: Speedometer gears for 3.54 rear ratio- C4 (Vettelover8360)
 

Take a look at this page: http://www.corvetteforum.net/c4/vett...Gearshtm.shtml
:flag

Re: Speedometer gears for 3.54 rear ratio- C4 (dgoodhue)
 

Since IM me saying you had 2.59's you will need

Drive Gear 12507670 Grey 15
Driven Gear 25513050 Purple 43
Vehicle Speed Sensor 10456091

Re: Speedometer gears for 3.54 rear ratio- C4 (Vettelover8360)
 

It had a 2.58 ratio.

Re: Speedometer gears for 3.54 rear ratio- C4 (Vettelover8360)
 

Thanks for the info!!! I looked at the page listed above ( ... Speedometergearshtm...) and I couldn't figure out how you knew the drive gear, the driven gear and the vehicle speed sensor. How did you do it? Thanks again!!!

Re: Speedometer gears for 3.54 rear ratio- C4 (Vettelover8360)
 

Actualy, how did you know which vehicle speed sensor? ;)

Re: Speedometer gears for 3.54 rear ratio- C4 (Vettelover8360)
 

For auto there are 2 different VSS; which one used depends on how many teeth the driven gear has. (Off the top of my head) one is for driven gear 41-45 teeth and the other is for 35-40 teeth. In 1991-3, the 6 speed and auto use different VSS. So I picked the auto VSS for the appopriate number of teeth (41-45 totth VSS)