I always use lead additive and this most recent fillup was with 91 octane too, which seems to help it run smoother.
Unfortunately didn't have much time to prep the truck but it did great the whole way. No overheating or any issue besides the battery connections not working once. We (a friend rode along/co-drove) repositioned the cables and it worked fine.
Made an air dam with the deepest lawn edging available at Menards (over a trimmed 2x6 wooden frame and bolted to the frame) and threw on the plywood tonneau my dad had been using to protect the bed.
Ended up with 15, 17, 17, averaging 16.3mpg over the whole trip. Wow!
I don't think I'll be driving this on the freeway enough to really warrant any more aeromods and likely will just remove the air dam and tonneau since I don't like that look on this old truck.
But it was a success!