Well, I got the truck. Great deal. 80,000 miles and he has the receipt for every single oil change, routine maintenance, etc. Even has receipt for wiper blades in his file. Meticulous maintenance from an 80 year old man, I love it. The longest OCI he ever went was 3,900 miles. He only went the extra 900 because he was on a long road trip.
I will change the oil this weekend. I have settled on PP 5w-20 with a Motorcraft filter. PP seems to have a lot of detergent and the idea of a squeaky clean engine sounds pretty good to me.
Thanks all.