I am redoing my 53 f100 bed, paint, new fenders and wood. I need the two center crossmembers for hidden bolt installation. Since Midfifties closed, where do I find them?

 

Mar-K should be able to provide the cross sills.

 

I checked their site didn't see anything

 

I don't think there is anything special about the hidden bolt crossmembers. You can just use a shorter bolt and a washer inside the crossmember instead of through the wood and crossmember.

ETA: Thinking back, maybe some of the reproduction crossmembers have a nut welded in them. I just held a nut with a big washer inside with a boxed end wrench. You can do either one with the regular crossmember.

A nut welded or with a washer on the other side of the hole marked with the circle:


Here are the MidFifty instructions to make your own hidden bolt crossmembers:

 

Thanks for Info Effie Trucker

 

I installed a custom gas tank under the second from rear bed cross member. I wanted to be able to remove the center two wood planks to allow the fuel pump to be accessed without removing the gas tank.

Since I cannot get access to the bottom of the cross member ( with the gas tank under it), I installed a 1”x1/8” steel strap with holes drilled to match the cross member. I welded captivated flange nuts to this strap, which allows me to put the bolts in from the top, without having access to the bottom.

Seeing the picture above, reminded me that I also welded the factory cross member mounting strap so it is much stronger than the factory spot welds, since I am using it to bolt the cross member to the frame. I am not running a large bolt through the top, and down through the frame.

 

Do new crossmembers come with that plate on the bottom where the bolt goes thru

 

I bought new cross members and they had the plate. I returned them and repaired the originals because the aftermarket replacements were slightly out of spec.

I just dropped a bolt down through the plate after I welded it better.

My frame was boxed and the only areas that I did not use captivated grade 8 flange nuts was the bed cross members because I did not want to make a mistake with lack of adjustment. I have 2” access holes in the frame boxing plates for access with grade 8 nuts and a strap welded to them to keep them from rotating in the frame. The bolts I used to drop through the cross member plates are Allen heads so I can access them through the cross member original bolt hole.

 

Yes. The originals have them as well.

 

Hello M2HB,
You wouldn't happen to have any pictures would you? Sorry I'm visual.

 

Bring your crossmembers over and I'll weld them up for you. I'd take a photo of mine but they're installed with a bunch of boxes stacked on top.

 

Thanks Chuck. I will take you up on that.