[Gregski]

Originally Posted by hatzie

More than you want to know about speedo gears in the 73-87 trucks. http://www.73-87.com/7387garage/drivetrain/speedo.htm

Nonsense, I love this stuff and you have no idea how much I appreciate you helping me out, thank you very much.

ok so I checked and I have the blue drive gear ie 18 teef so using their formula it validates that I need the 43 tooth driven gear.

18 x 3.42 x (20168/29) = 42.76 or round up to 43