Also a quick but not always accurate way of determine a tubeless rim from a tube type is the tire size.
The vast majority of truck tires/rims that are tubeless will be half sizes like 16.5", 17.5", 19.5", 22.5",and 24.5"
And tube type will usually be whole sizes.
But there are exceptions.

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
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-