Electric pickup fitment matters because equipment must work with the truck's body, load limits, electronics, and electric-specific systems. A rack that attaches to the bed may still obstruct a camera, a wheel may have the wrong rating despite matching the bolt pattern, and a charging adapter may connect physically without being approved for that use.
Begin with the exact model year, configuration, and accessory combination. Use vehicle and equipment instructions to confirm mounting, clearance, wiring, charging compatibility, and required setup. Familiarity with a related gasoline truck is useful background, but it is not evidence that the same parts or installation points apply to the electric version.