Power Steering Pressure Hose

[Primer70]

What's the difference between the 73 - 79 power steering box & pumps and the 80 - 91 power steering box & pumps? What I've got is a 1973 Suburban that in the next week or two I'll be installing a 1991 engine with the serpentine belt accessories on it with the 1991 power steering pump. I'm assuming the 73 - 79 power steering box & pumps are SAE standard threaded and the 80 - 91 power steering box & pumps are metric threaded. If this is so is there a power steering pressure hose made for this kinda swap? If not I guess I'll have to have a local hydraulic supply shop make me one.