Installing the mounts was a fairly elaborate process.
The factory hole diameter for the mounts and rivets was .402.
I intended to use 7/16 an bolts and metal locking nuts. This required the mount holes to be up sized to 7/16 (.4375). For best shear load capability of the assembly the holes would have to be reamed for a close tolerance fit of .001 bolt to hole fit.
1)I first bored the mount holes to .430 and then reamed them up to 7/16 in two stages .434 and .4375 on the mill.
2) I drilled the top frame mounting hole and finish reamed it to .7/16 in s steps.
3) bolted the mount in place and made sire the location was spot on.
4) transfer punched the lower hole location through the mount then drilled and reamed the lower hole through the mount. Repeated the process 3 more times.
5) re drilled the 4 rear mount holes ( 1-1/2" back) and removed the unneeded frame extension for mounting the service bed..
I made sure all holes were clean and burr free. Installed the mounts and torqued the bolts to 45 ft/lb. This is the high spec found in the faa ac 43.13 book for the an bolt and nut used.
The truck leans left and I found a spring spacer above the right rear spring. It's probably to level the truck when the camper was on it. I don't need it now. I might add one to the left for a bit more lift and do a similar thing to the front.
Next to test fit the bed and determine if any pad height correction is needed for correct lines and reveals. I will be installing 1/4" rubber pads at each location like the factory. The front two mount pairs get a spring arrangement probably to allow movement while flexing so that will be duplicated as well.
Hardware used:
an363-720 nut
an7-7a bolt undrilled (7/16 grip)
an7-10a bolt undrilled (1/2 grip)
an960-716 washer to achieve proper nut engagement and prevent bottoming on the shank.
