Okie,
The 17.5" XTAs are narrower by maybe 1"--and the height is within 1/4" of the 16" G614s. They are a super replacement for the 16s. Absolutely NO clearance problem.
I made this changeout 5+ years ago and have not had a flat/blowout, and add air only once a year.
Got the wheels/tires from
www.trailertiresandwheels.com in Edon, OH. They will ship wheel/tire anywhere already mounted and balanced.
If you need a tire upgrade, this is a no-brainer. However, some people worry about the 62mph limit Michelin says not to exceed--I haven't adhered to that when needed, but I usually run 60-65. I don't worry even when I find myself above 70 when conditions permit.
Joe