Placement of Reese standard bed rails?

bpounds wrote:
The frame kit you selected has fixed centers for the rails, unlike the universal style kit. So the rough center distance for the rails is determined for you. You need the hitch base to fine tune the fit.

Here is the install PDF which shows how the frame adapter ears will determine the rail centers.

I guess the hitch base would help, it certainly isn't needed, the industry standard rails need to be 22" centers, and thats where those custom braces will set them ,yes the holes are slotted so you do have to use a tape measure to set the 22" before drilling. All I did was set them , and squared them. The bed rails have the square holes, I just drilled a small pilot hole in the center of those holes , maybe an 1/8", put the bed rails out of the way,then opened them up for the bolts .