Using the RPM calculator at the bottom of this page:1960 261 in 1954 3100
3.55 R&P (enclosed driveshaft)
Tire diameter (rolling diameter) = 31.5 inches
MPH = 65 (I have cruised at this speed for hours on Interstate Highways)
Final gear ratio = 1:1 (SM420 4-speed)
RPM = 2461
The highest RPM that I have reached was 3522 (for a few seconds)
