Originally Posted by Volfandt
I don't know the rpm but the sweet spot on my 49 1/2 ton 3100 is between 40 - 45 MPH....

I've run it up to 65 but only held it there long enough to complete the pass. It lets me know me it doesn't like spinning that fast grin

Engine is a stock 216 & 3 speed tranny, 4.11 gears and 30" tall (R225-16) tires.

Good luck
Dave
RPM Data for Dave's Truck:
2992 RPM @ 65 MPH
2071 RPM @ 45 MPH
1841 RPM @ 40 MPH

thumbs_up John