K100 power steering upgrade

Aw, come on, real truck drivers don't need power steering, yeah, like I should talk. I started right when PS was becoming popular, late 70s. The 1st company I drove for, they had an older R model Mack with manual steering, and was a beast. Let's just say we put off telling the boss of problems so we didn't have to drive it. Practically every truck in 40 years had PS, even the very 1st HD truck I drove, a '63 IH R190 tandem dump.
The air assist is a great idea, I drove a Mack once that had that. It actually worked quite well without near the plumbing of hydraulic assist. You had the feel of manual, but "assistance" when needed. The only downside, is backing in, they take a lot of air, and can easily"run out" with impatient dock workers wondering what's the delay. I thought all Cummins had a cover below the air compressor, and the tank will be the hard part. I've had many that made it's own tower off the frame, and funky hose routing too, but well worth it. I don't ever recall a PS being belt driven. Maybe on an old Detroit.
I drove a truck like yours for a cranberry marsh shuttling wagons. It was an old Moodie truck, from Stevens Point( remember them?) and had no PS. I was just going across their yard, but I can see how a cabover is worse. Now, my old '72 Pete 359 had manual steering, but had "center point steering" and was a bit easier, but I'd go to a truck boneyard, find an old KWhopper, and pull everything off that. Good luck, it's a big job.