I just got my rear axle ratio changed to 3.73 on my 69 Camaro.

I now need some help with finding the right speedo gears.

Here's the specs that I have:

TH350, 3.73 and 235/60-R15 Tires (26.1" Diam.).

I can calculate the Driven Gear which should be the Yellow (24 teeth) one according to the formulas.

I need help with the Driving Gear, Rick's First Gens offer 4 different ones. I called them to find out which one I needed, they told me to try them out and use the one that fit.

Thanks,
Daniel.

Maybe this link might help you out:

http://www.tciauto.com/tech_info/speedo_gears.htm

Thanks magisnyc,

I used their program and also sent them a email with the question.

They have been very nice and quick, they recommended that I use the following gears:

10 tooth drive gear and a 29 tooth driven gear

The only problem is to get the 10 tooth drive gear, they recommend going to a GM dealer but my local dealer said that they are discontinued.

Question:

Were can I could get both the drive & driven
gears.

Note: Rick's doesn't have both in their
catalogue.

Thanks,
Daniel.