I'm having problems finding a coolant bypass line (L - shape metal tube) that rubber hose connect to one end and other goes into rear of engine block by corner of intake manifold. Need one for '97 Ford 150 5.4L, can't find any at local autozone...etc Maybe some of the newer yr part# work for these?

 

I know extactly what you're talking about. I think the ARE the same for many years on the f series (as long it wasn't the expedition with twin heater, you should be fine.)
I would also think that this is most likely a dealer only item. Possibly a junkyard could help you too.