Bed cross sill not lining up with frame pad 1966 C10 SW

[Steveoreno]

Now this is an odd one.....thought I would go ahead and mount my bed cross sills just to get them out of the paint bay so I could start paint work on the box sides, wheel houses, etc. When I went to mount the intermediate sill (the second one back from the cab) the holes would not line up...not even close. Thinking that perhaps one of the sills in the kit must have different hole spacing I checked all three and they are identical. The bed sill holes are 35 1/2" and 31 1/2" apart on all three while the holes in the frame pad are 37 1/2" center to center. So the solution apparently is to drill new holes in the intermediate sill to fit the frame pads....this would leave me wondering whether or not the holes would then be out of alignment if I ordered pre-drilled bed wood...or should I just assume that they would not line up and order non-drilled bed wood. My biggest question is why this is so....should one of the reproduction sills have been drilled different than the other two....is my truck an anomaly.....what the heck? The width of my frame on my 66 C10 short wide is 30 1/4" inside to inside at the center point of the intermediate mounting pad location. The picture shows the silver marker where the frame perch holes fall on the sill when it is lined up. Any ideas?

[Steveoreno]

here is a shot showing the mounting perches....

[MT65]

I had something similar, same bed sill, ended up welding tabs to match holes in bedside and redrilling holes in frame pads, truly a pain, but was the least painful of the other options…reason…no clue, truck came to me in every piece it could be in..and finish painted…and nothing prefit beforehand…

[rbruno68]

I chose not to drill through the bed wood for the bolt to attach the bed. I was worried that after all the work to make the wood and the staining that if ended up in the wrong spot, I would have ruined a piece of wood and have to find a replacement. I drilled a relief pocket on the bottom of the wood to clear the bolt heads. I am glad I did. My same sill was out of place and I had to drill to enlarge the hole. If I had measured and predrilled the bolt hole, it would have been off. I was using an original sill, but the difference on mine is that at some point in its life, my truck had damage to the rear corner of the bed and it moved things off square. With the damage and with me trying to square everything, it just didn't line up. So, long story short, I drilled a hole in the frame, bolted the bed down, and hid the bolt heads under the wood.

[bigmoe]

Originally Posted by rbruno68

I chose not to drill through the bed wood for the bolt to attach the bed. I was worried that after all the work to make the wood and the staining that if ended up in the wrong spot, I would have ruined a piece of wood and have to find a replacement. I drilled a relief pocket on the bottom of the wood to clear the bolt heads. I am glad I did. My same sill was out of place and I had to drill to enlarge the hole. If I had measured and predrilled the bolt hole, it would have been off. I was using an original sill, but the difference on mine is that at some point in its life, my truck had damage to the rear corner of the bed and it moved things off square. With the damage and with me trying to square everything, it just didn't line up. So, long story short, I drilled a hole in the frame, bolted the bed down, and hid the bolt heads under the wood.

I did the same thing.

[Steveoreno]

Well its nice to know that I am not alone with this issue...still can't explain why it is ......but it is what it is. I decided to drill new holes in the cross sill to align with the existing frame perch holes.....not knowing now if these new locations are in alignment with pre-drilled bed wood, and not having the wood here, I decided to get the wood undrilled (ordering today), then I will mount up the box, square everything up and snug it up, then mark the locations on the wood from the underside, and drill it to match what I have. I thought about going with the hidden bolts as suggested but the truck is a very mild restomod and I am trying my best to keep it as it would have looked in 66 with the exception of the stance and running gear. Thanks for the replies guys, I really appreciate it!

[jayoldschool]

The different sills (front to back) have different pad locations and holes. Mine were rotted, so I got used ones from someone here. Needed to move a couple pads and drill a few holes, but the welder and a drill took care of things quick. No problem mounting up the bed.

[SkinnyG]

Yes, ^^^^ This ^^^^

[MT65]

Originally Posted by MT65

I had something similar, same bed sill, ended up welding tabs to match holes in bedside and redrilling holes in frame pads, truly a pain, but was the least painful of the other options…reason…no clue, truck came to me in every piece it could be in..and finish painted…and nothing prefit beforehand…

This is the finished bed that had the second cross sill issues, the sills had been numbered front to rear by the shop the disassembled it, the only one that was necessary to modify was the second from the front, yes, it gained two bolts to the frame however didn’t have to mess with the bedside holes…

[Steveoreno]

MT65, that looks beautiful! Nice work!! Thanks for your input!!