I'll be installing my 5th wheel hitch from my 98 DC into my 2001 DC. It all looks pretty straight forward but I'm not sure what size drill bit to use for the studs throught the frame rails. The threaded part is 1/2" and the splined part alittle bigger. I'm not sure if the holes should be 1/2" and the studs will pull into place with the nuts tightening down on them or if the holes need to be slightly bigger to allow them to pull in. Maybe 17/32" or more. Anyone have directions or experience installing a Reese bedrail kit? I tried the Reese website but it doesn't come up. Any help much appreciated...