Fleet side bed floor cross sills???

[RyanNewberry]

I got a cross sill on my bed floor that needs replacing. I could just patch it but I am curious what everyone else does. I looked at lmc, key parts, rock auto, and brothers, they only have listings for stepsides. With that I know the stepsides cross sills will be shorter but are they the same dimensions as fleet sides? Height and width wise anyway? Thanks in advance.

[dragonball98312]

You have a fleetside with a wood floor? Im looking to redo mine aswell

[dragonball98312]

I was curious if the wood from a 72 or lower long bed fleetside with woodfloor would be the same as 73 plus.

[RyanNewberry]

No it’s a steel floor, cross sills might be the wrong term, the cross members underneath the floor that the bed bolts go through.

[ray_mcavoy]

Originally Posted by RyanNewberry

No it’s a steel floor, cross sills might be the wrong term, the cross members underneath the floor that the bed bolts go through.

Yes, cross sills is the correct name for those parts.

However, the cross sills used with wood floors (which includes all 73-87 stepsides) aren't as tall as the ones used with a steel floor. Since the wood planks are thicker than a steel floor, they use cross sills that aren't as tall so the top surface of the wood bed floor ends up being the same height off the frame as the top surface of a steel floor.

I suppose you could still use cross sills meant for a wood floor but you would have to add some shims between the bottom of the sill and the truck frame to take up the height difference. And rather than use the shorter stepside cross sills, the ones made for 67-72 fleetsides would probably be a better fit.

Originally Posted by dragonball98312

I was curious if the wood from a 72 or lower long bed fleetside with woodfloor would be the same as 73 plus.

No, it's quite a bit different. The 72 & earlier fleetside beds w/wood floor had the wood running all the way out to the edges. And the wheel tubs & bedsides had flanges along the inner edge that bolted down on top of the wood (or steel floor). But 73-up changed to having the bedside-to-floor & wheel tub-to-floor bolts going sideways into the edge of the floor. So when the 73-80 long fleetsides were optioned with the RPO E81 wood floor, they used some special flange pieces around the perimeter of the bed to adapt the bedsides & wheel tubs to the wood floor. Those flange pieces are several inches wide so the wood doesn't run out as close to the edges of the bed as it did for earlier years.

[cadillac_al]

I'm surprised somebody doesn't make those cross sills. I always figured if I was going to restore a bed floor I would have my local sheet metal shop bend me some cross sills by supplying the measurements.

[Danmcg]

Look up SHERMAN 89879C I think this is what you're looking for.
But like CA mentioned, I'd go to a local sheet metal shop and see what it would cost for them to make them for you.

[Dads79GMC]

I talked via email with Audry at Mar-K asking about the LWB wood floor cross sills. I thinking about replacing the cross sills on my fabricated SWB wood floor. I had contacted her last summer and couldn't find the email, so I contacted her again. I think you could use this cross sill if you put some square shims between the cross sill and the frame???? Here is Audry's feedback to me:

"We discussed this last July and I recommended using part #100707, which fits a 1958-72 GM Fleetside wood floor. It has no holes drilled in it. It’s measurements are: 72” long x 2 3/16” tall x 2 15/16” wide."

I just went out and measured the ones on my steel SWB bed floor and they are 3" tall, that would be a lot of shimming.

Mike

[RADustin]

why dont you ask someone to cut them from an otherwise rusty bedfloor and ship?

they can hack the floor and you can clean it up and you're ready to go with an OEM repair.

Jeff @ azpartslocator has done this for me in the past for a transmission tunnel.