Bed Support "Cross Sill" Options

[scrap--metal]

My truck needs rear bed support rails, or "cross sills" as LMC calls them. It needs them bad... They're currently unavailable through LMC (backordered). Are there any other sources for reproduction parts?

I checked Brothers (now Holley) and AMD, but couldn't find the parts from either of them. Certifit (a.k.a. sorta-fit) didn't offer them in their catalog either. Please let me know if any of you are aware of any other sources.

Ultimately, I'm trying to keep my K10 on the road for a little while longer. I haven't been able to find a usable bed up here for less than $500. One guy wanted $750 for one needing work to be usable. If I'm going to need to cut and weld, I might as well do the work to the rusty junk I already own. At least that's my current frame of mind.

 

[TotalyHucked]

Got any pics of what you're working with? I work at AMD, we only offer the rear cross sill because customer typically need the whole floor if they're replacing supports/sills.

Rear cross sill:

Rear Tail Pan / Cross Rail Assembly - Complete - 73-86 Chevy GMC C/K Fleetside Pickup; 87-91 Chevy GMC R/V Fleetside Pickup; w/ Steel Bed Floor Cross Sills | Triplus 900-4073-1

Complete rear tail pan / cross rail assembly for 73-86 Chevy GMC C/K Fleetside Pickup & 87-91 Chevy GMC R/V Fleetside Pickup. Correct for use on models with a steel bed floor only. This is rear most cross sill under tailgate. Stamped from high quality hea

www.autometaldirect.com

And also one you can use as a patch if needed:

Cross Rail - Rear - Outer Patch Only - 73-91 Chevy GMC C/K Fleetside Pickup; w/ Steel Bed Floor Cross Sills | Triplus 900-4073

Replace your damaged or worn out Rear Cross Rail Outer Patch with this high-quality replacement part designed for 73-91 Chevy GMC C/K or R/V Fleetside Pickup. Order now and give your truck the protection and appearance it deserves.

www.autometaldirect.com

 

[Camar068]

buddy took some U channel and cut/split/welded them to length/height. I'm not a welder so it's not an option for me....have to farm it out.

 

[scrap--metal]

Got any pics of what you're working with? I work at AMD, we only offer the rear cross sill because customer typically need the whole floor if they're replacing supports/sills.

What I'm working with is essentially junk. And it's even worse than I thought. I hadn't been under the bed since last fall. The rear sills, partially pictured below, are what I was initially asking about and looking for. The front sills are now junk as well. And the rear most cross sill, as offered by AMD, is also necessary.

I can't justify investing in all those pieces to keep this bed in service. The bed sides are junk and it's got its share of dents and dings inside. I'm confident that I need to find a different bed.

You must be registered for see images attach

 

[TotalyHucked]

Yeah, I'd agree with that statement unfortunately

 

[etc86]

Hey guys, hope everyone is ok with me jumping in. I’m currently going through a similar process with my 75 c20. I’d buy them but I live in Australia and freight is a killer so I’ll be fabricating them myself. Does anyone know the measurement from chassis to bed floor at the front of the bed near the cab and above the back wheels? I’ve asked in other forums but helpful people keep telling me to buy them. Thanks in advance.

 

[75gmck25]

I have a 1975 Truck Specifications document in PDF that might have some of the measurements you need. However, when I tried to attach it to my post it was too large.

I’ll see if I can compress it or create a zip file that can be attached. On my iPad right now and I don’t have the software I need to change the file size.

Bruce

 

[etc86]

Thanks for that Bruce. I found those myself and came up with a rough measurement. I’m looking at roughly 2.9 inches for the main cross sills and I’ll work out the Center ones from the chassis height difference. I’m surprised that nowhere has the actual specs for them though.

 

[Rusty Nail]

L.K.Q. may be a source? They inventory their parts online and might be worth a click.

 

[etc86]

Thanks for the tip Rusty. Unfortunately they only go back to 1995 though so no love. But with the scale drawing I found I should be pretty close. A guy on another forum got back to me about it as well and he’s going to measure his on the weekend. I’ll make it work somehow, the rest of the thing is put together out of luck and persistence so may as well continue the theme.

 

[daven]

Try NPD

 

[etc86]

NPD was a no go. I really just need a height. Buying anything will cost more in shipping than it’s worth really. I’ll either get some bent up or if they’re pretty close to a standard top hat/purling size I’ll use that and then shim or shave as needed. I’ve pretty much got it figured out though. Cab height and bed height will be the same off the chassis close to where they meet. I can work the rest out from there.

 

[Rickf]

If you're not looking for a 100 point trophy, what about box/rectangular tubing? I will neither confirm or deny I've used PT 2x4's.

 

[DanMcG]

I'm a little late to the party here, Are you looking for dimensions for these cross sills?

You must be registered for see images attach

A quick measurement looks like 3" and another is 2.9" I can look closer if you need more info.

 

[etc86]

Never too late. Even if I didn’t need them, which I do, someone would have eventually. I was pretty much at that myself but nice to confirm. So the one’s between the wheel arches, are they around 1.5?