There are several types of lug nuts in use on wheels, and when changing wheels it may be necessary to change the lugs as well. These days you’re most likely to find wheels using acorn lug nuts with 60-degree conical seats. Some aluminum wheels do use a mag lug that is not tapered and has a shank area that fits into the wheel stud hole. These types are not interchangeable.
Another light truck tire size convention such as this lists the dimensions much more clearly. For instance, a 35x12.50R15LT tire is nominally 35 inches tall, 12.5 inches wide (overall), and mounts to a 15-inch wheel. Actual tire dimensions for any given size can vary between manufacturers. For example, one 35-inch tire may measure a true 35 inches tall, while another may be shy at 34 inches.
Wheels on IFS trucks have much more backspacing than those that originally came on straight axle trucks. Most OEM IFS type wheels won’t bolt on a straight axle due to interference with the brake calipers and steering arms. On the flip side, using wheels with much less backspacing on an IFS truck will push the tires far outside the fenders.
Wheel width can play a part of tire performance. It affects the sidewall and tread shape and how they flex against the terrain. The wheel width will also determine the amount of sidewall bulge beyond the wheel edge. In general, wider wheels will offer more footprint and flotation for the given tire as opposed to using a narrow wheel. However, narrow wheels typically allow you to run lower air pressure without pushing the tire off the wheel bead.
If you’re putting new wheels on a heavy truck or going with large tires, consider the load rating or maximum tire size rating specified for the wheels you’re considering. Some wheels that may fit on a truck are not designed to withstand off-road loading or tire sizes over about 33 inches.