NorthStar offers a riser constructed of 2×2 around the perimeter with several pieces running crosswise. Our Hallmark also had the same. Lots of folks on the Internet report using foam board, so lots of ways to get a bump in height. With the standard NorthStar riser our camper clears the marker lights on the roof of our cab by about 1″, but I wouldn’t mind a bit more.
Steve and Andra
2012 F350 6.2 gasser SRW LB
Fab Fours front and rear in case we run into a rhino
2019 Northstar Laredo SC