I personally prefer to use my TB coolant lines. They help the engine heat up faster in the winter.

Anyway, I don't know what year your truck is, but in my 91, the top hose runs back to a nipple on the radiator neck; and the bottom hose hooks into the thermostat housing.

For the top hose, I originally had a steel line that hooked into the radiator neck, ran across the fan shroud, and then turned into rubber to hook to the TB. However, that line ended up clogging with sludge so I replaced it with a rubber hose.