Truck bed cover....

OP - are you talking about clearance between the bed rails and the underside of the fiver or clearance between the Tonneau rails on the side and the back of the pin box? The latter is more often an issue than the former.

Rob

I have a rollup tonneau and still have 6-7 inches of clearance. However I'd buy a trifold type if I was doing it all over. The rollup is almost impossible to lock in a partially rolled up condition. That would be the case when you are hooked to the fiver. I want the front of the bed under cover so that boxes of gear and tools ect don't get wet when it rains while towing. With a trifold you could fold it so the front third of the bed is covered.

I have a TonnoPro vinyl tri-fold that I leave on all the time (fold forward when running). It's not a problem for clearance in my case with a SuperGlide hitch, but I have 6" from bed sides to fiver.

If you are talking about the kind of cover that has a track mounted to the top of each bed rail, as long as there is 6 inches between that track and the 5er you should be ok. We have slightly less than 6 inches and have been ok taking it slow through some very uneven forest roads. We don't have a cover though.