Sounds like my kind of truck as I love to shift.
65 MPH sounds about right in your truck. My truck would top out at 62.
You may want to have a mechanic, who knows the old Detroit's, to check out the governor to make sure it is adjusted right.
One thing about a Road Ranger tho, is that it shifts very differnet than a regular 4 Speed or 5 Speed trans. You actually have to shift it pretty fast. Very unlike many of the new trucks today that can practically have a lunch break between shifts. Especially true with a high revving Detroit. Once taking off in first gear, you really need to keep up a fast rythem of high revving and fast shifting. Just slightly hesitating in nuetral while double clutching. Once you have the rythem you won't even need the tach as mentined earlier. The old Detroit's also produce their power more at the higher RPMs.
Now downshifting is a whole differnt story and a Road Ranger is also different there too.
