I recently bought all the stuff I need to install 3.73 gears as well as to put posi into my rear end, I know with this upgrade to my stock 91 rs it will throw off the speedo and i know that this can be fixed by replacing to speedo gears in the tail end of my transmission what i dont know is what gears are needed to make my speedo accurate again , I belive that i was told that i will need the 15 tooth driving gear, but I dont know if this is correct or what type of other gears i need. I know that the tire size factors into the what speedo gears are needed and I have 225/55R17 tires and wheels what gear would be used for them. I have read some stuff posted about a forumla that I can use to caculate it but it is confussing to me any info would help me out alot
Thanks

 

Phone the following company. They'll fix you up.

http://www.transmissioncenter.net/sp...n_______va.htm

JamesC

 

You could/ve just PMed me, but to be safe, use a 41 tooth driven gear, the part number for your local GM stealership can be found in my other sticky.

 

You need a 42 tooth driven gear.

 

can also be done with computer chip re-burn.....I know your probably not at that point yet, but the 91' - are computer controlled and can be done both ways....just some info...

 

thanks for the info

 

i own a 92 rs and just changed my rear to a 3.23 from a 2.73 any body know of the top of their head what tooth i'll need and is it the one that pulls out where the speed sensor is ?