Modern tires are wider. Most modern trucks have power steering.
1986 Suburban with 16" rims = 8 lugs. 6.5" width. Hubcap nubs.
1986 Suburban with 15" rims = 6 lugs. 5.5" width. Hubcap nubs.
The original tires are narrow to make it easier to steer. No power steering.
1954 Chevrolet 3100 16" rims = 6 lugs. 4.5" width. Hubcap clips.
If you are going with stock 54 rims then you need a hubcap made specifically for the clip style rim.
Make sure your clips are in good condition. They can be replaced.
Example of caps without the Chevrolet bowtie embossing:
https://hubcapmike.com/baby-moon-hubcaps-for-40-63-chevy-truck-chevrolet-truck-moons/