Thanks for the advice.
The truck spends most of its time empty, cold starts are infrequent, and the use is more highway than city. It never gets below freezing or above 92F here.
Therefore, I'd probably do just fine with darn near anything for 5k intervals. I passed the 3k mark with Exxon Superflo 10W-30 and the oil looks so good that I've decided to keep going. I might drain and have it analyzed at 5k.
I do like the idea of a 15W-40 universal, since I can run it in the bikes as well. Maybe I'll give Pennzoil a go and see if all that moly makes my wet clutches go on strike.
The reason why I posted is because the psychological 3k barrier is a tough one to crack. I swear I hear the truck in my sleep, asking me to change its oil.