How much clearance is needed between the front of camper to front of truck bed. If my rubber bumpers touch the front of bed, I only have .5 inch at the top.
That's 1/2" more than I got. But then, I don't have the rubber bumpers either. My Lance has some plastic strips. Two of those that run vertical and makes full contact with the truck bed at the top. (Top of the truck bed)
In this photo, you can see the strips as they are black. The truck bed runs just below those two vents, which are for the batteries under the step to the cab-over bed.