What am I doing wrong with this bed install?

[jcwren]

Got all the boards position, cross sills in place, dropped the front end of the bed on to the perches, went to drop the back end, and its high centering on the floating sill.

I have a total of 6 cross sills. The one closest to the cab, 2nd is at the next set of bolt holes back, 3rd sill at the 3rd bolts hole set, floating sill at the 5th set, 4th sill at the 7th set, and the 6th sill at the 8th set (not counting the bolt holes that go through the piece of angle that's attached to the head plate).

It doesn't appear to make any sense for the floating sill to be anywhere else, otherwise there's a long expanse of no support.

I cannot find a single dang picture on the intarwebs that shows how these ought to be arranged, and nothing in the FSMs that I can find.

(Not sure why the pictures are rotated, they're correct on my phone and on the PC).

[burningsquirrels]

Clearer pic. It's high-centering where the light is on that floating sill.

[FirstOwner69]

From the Mar-K bed assembly for a fleetside LWB. Not sure if the stepsides are different.

17. Attach the cross sills to these bolts from the bed side lower flanges and the short bed strips. See figure 7. The first cross sill connects to the second bed strip hole that is 3-3/8 inches back from the front of the bed. The second cross sill connects to the third bed strip hole that is 15-3/8 inches back from the front. The third cross sill attaches to the bed strip hole 26-3/4 inches from the front of the bed. The fourth cross sill connects to the eighth bed strip hole at 72-1/2 inches from the front, which coincides with the rear of the wheel well. The fifth cross sill connects to the ninth bed strip hole at 83 inches from the front. There are two smaller cross members located at the front or beginning of the wheel well and at 60-1/8 inches from the front of the bed. One reinforcement strip is 72” and one is 49-1/2”. Attach these reinforcement strips to the bolts from the bed sides and the wheel well. Mount the 72” at the front of the wheel well and the 49-1/2” reinforcement strip fits between the wheelhouses at 60-1/8 inches.

[jcwren]

Awesome, thanks!. I need to move the 72" reinforcement back one set of holes. Apparently I don't have the 49-1/2" strip. And the bolt kit I have doesn't have the correct number of bolts to accommodate it. However, considering the biggest load this bed is going is going to see is a couple lawn chairs and a cooler, I don't think I need to sweat that one.