texasjayco wrote:
...I’m pretty sure my 42ft 5er (13.4 tall) would not fit through there!!...
According to the 
Park's website there is both a height and length restriction. 
Prohibited Vehicles
Vehicles over 13 feet 1 inch tall, Semi-trucks, vehicles carrying hazardous materials, vehicles weighing more than 50,000 pounds, single vehicles over 40 feet long, combined vehicles over 50 feet long...
I doubt your truck and 42' 5er are less than 50' long and unlike a motorhome and toad you do not have the option of unhooking to drive each separately.