I (am again) driving commercially: Plan your move as to distances. "Legs" to accomplish at abut 100-miles/2-hours to stop for rest breaks. The trick here is to find the easiest on/off places to stop (such as Interstate rest areas). Plan your fuel stps with the same care (same side of road, prefeably beyond any stoplights; e.g., a truck stop on the same direction frontage road
but past the overpass intersection. The fuel stop can coincide with the four-hour "one hour break" for both fuel and a meal.
The biggest road will be best (Interstate) over any other type. I can often trip plan so that more miles on the big road works better than a shorter total distance over secondary and tertiary roads. A straight line on the map is helpful for looking at alternative routing. The number of deceleration and acceleration events is crucial to finding the best compromise.
Some partss of trip-planning are simple: Don't traverse major metro areas between 0600 and 2100 if possible . . but that conflicts with not driving after dark. So work out compromises, such as shutting down about 50-75-miles from that big city ahead until o'dark-thirty tomorrow morning. Etc.
A vacuum gauge in drivers line-of-sight on dashboard will provide feedback (a tach next to it if not already fitted with same).
An old bomber like that needs best mechanical baseline. Tires are of greatest concern, and new shock absorbers are recommended.
Chasing after steering slop will pay the biggest dividend as mohos are notoriously bad. Keep brakes tightly adjusted and
be sure that balljoints/kingpins are in good shape.
A MAJOR tune-up is recommended. Look that up.
Proper weighing is the first step. Do it with full fresh water, full propane and loaded for travel at a CAT Scale.
PDF
http://www.rma.org/tire_care_info/ti...0311_FINAL.pdf
Correct any side-to-side imbalances. Inflate tires to load versus pressure guidelines by tire manufacturer. And start this by being sure that tires are actually correct for your vehicle . .
don't assume that they are!!
.