What is the correct hitch height using a B&W companion hitch, 349m and 21 F-450? There are 3 hole sets that allow you to position the plate low, mid or high. Curious what others are doing to get the proper top of bed to underside of RV clearance.

Also, is there a height issue with either of these positions that will push you above 13'-6" overall height?

I searched but couldn't find info on this combination so apologize if this was discuss already and I couldn't locate it.

Thanks