Gear Ratio/Speedo Gear table

[justacruzr2]

Does anyone know if a table exists that shows rear end gear ratios and what speedo gear is used with each.

 

[ELCAM]

A parts illustrated has this.

1984 Chevy.

 

[olds307 and 403]

TCI has one.

TCI Auto Speedometer Gear Calculator - TCI® Auto

Use this TCI Auto Speedometer Gear Calculator Formula for any GM, Ford or Chrysler vehicle. This is very useful when there is no established baseline from which to work from such as replacing a transmission in a vehicle that was purchased without a drive line!

www.tciauto.com

 

[justacruzr2]

Thanks but I'm not sure how to use it. What I do know is that the car has P195 75R14 tires, TH350C trans and 2.41 axle ratio (code 2AJ from the build sheet). The speedo gear came from the car that was the donor for this project and it had same tires, TH250C trans and 2.29 axle ratio (code 2AH from the build sheet). It feels like the car is going faster than the speedo says but I could be wrong. The difference between the 2 axle ratios is only .12 and seems like a very small difference.

 

[oldsofb]

Use your phone to check speed against the speedo.

 

[78Delta88]

Old school method. Get on the highway. Set speed to 60MPH. As you get to a mile marker, start your stop watch.

As you get to next mile marker, click stopwatch to stop it. Read result.

Less than 60 sec, you are faster.
More than 60 sec, you are slower.

60 MPH is one mile per minute (60 Sec).