The 69 Camaro I purchased has a speedo issue that I am hoping you guys can help guide me in fixing this. It is reading 80 mph when I am doing 35 or so. I'm not sure if I attack this from the speedo or from the transmission side where the cable attaches. I'm assuming I need some different gears in either of the 2 places but don't have a clue where to start on this one. The car is a 396 with turbo 350, 2800 stall converter, 10 bolt posi with 3.73 gears. Any guidance would be appreciated. Thanks, Scott

 

You need to change the speedometer driven gear (what the cable connects to at the trans), and possibly the drive gear (on the output shaft, inside the tail housing of the trans).
How to calculate what gears you'll need: Speedometer Gear Calculator and Charts - TCIŽ Auto

 

Thank you for the info. Seems fairly easy.

 

Not hard, but could end up being a little time consuming. If you have to change the drive gear, which is likely, you'll need to drop the driveshaft out to remove the tail housing.