Dan,
if you can look up your tire size here The Tire Rack you will find the rev/mile. If you multiply that figure by the rearend ratio (I believe stock should be 4.11) you will get the RPM at 60 mph. In my 1 Ton it works out to around 2700 RPM. I do run at 60 mph when required with no problem with my 216, however most of my higher speed driving is done at 50 mph.

1951 GMC 1 Ton Flatbed -- It is finally on the road and what a great time I have driving it!
1951 1 Ton Completed

My Chevy Master 4 Door is on the Road!