yup, ford all the way. I'm not a ford or chevy guy. More of a car, "in general", guy..haha.
I've concluded that in my opinion, mid-80's - early 90's chevy's are simply not there in the reliability department.
If those are your two choices, I'd definitely say the Ford. I've seen 4-5 fords of that vintage, two with 360's and two with the diesel 7.3L up close and personal in the last few months, and all of the owners (one is my dad) report no major issues and I swear the paint and interiors on all of them (other than the bed area) looked pretty much brand new with no noticable wear on the fabric or plastics.
The TTB front axle is a bit complicated in it's design, but other than some examples go through ball joints at an excellerated rate (probably due mostly to bigger tires and/or being lifted) they seem to do just fine, though I personally would rather go with a solid axle front if given the choice.
My dad's HAS had one issue with the technology used to switch between fuel tanks, but it was fixed very easy with the replacement of a solonoid, relay or whatever lets the system know what tank to choose. (Sorry, I forget the specifics of how the truck controls that duel tank supply)