I think the 61 F350 I had came with 17.5" tires.
I was glad to get rid of them, as the 17.5" tires are a little difficult to find, and expensive.
Was able to sell the wheels as someone wanted tubeless even at that cost.
They were not the right bolt pattern for an AD truck though.

Even if you found 17.5" wheels with the correct 8 lug pattern, I think the 19.5" wheels will be the more economical option, and better chance of finding a tire if you need one while on a trip.

Grigg

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
---All pictures---
"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-