[MaSnaka]

FF2,
when your cruising at 60 make sure your in 4th gear and not your overdrive. 4th gear should be 1/1. At 60 mph in 4th gear with 28.75" dia tires you should be taching between 2686-2593 rpms. My chart only shows 3.73 rear at 28" and 29", so it's just a ballpark estimate but should be close enough. Like Danc30 said 1 tire rotation and 3 1/4 turn of the drive shaft would be 3.25. If you have 3.70 gears then you would see almost 3 3/4 revolutions of the drive shaft.

John