Ok gang,

My 56 F100 is coming along well. My truck WAS a long bed chassis. I have shortened the chassis by cutting the back extension off which has allowed me to fit a short bed box on the chassis.

The issue I currently have is that all the crossmembers on the short bed were in the incorrect locations or wrecked. I plan on bending up some new crossmembers at work, but I need to get the bed sitting where it should be.

I have the bed sitting on the chassis and the stock bolting location at the rear. As for the front I have supported the bulkhead with some 2x4's to try to get a good height. Right now I have 4.25 inches set in the front.


Anyone have an LONG bed truck that could measure the height of their front crossmember from the chassis to the bottom of the bulkhead? Or from the chassis to the top of the bulkhead?

 

Uh, I have a question. What are you planning to do about the difference in wheelbase between the short bed and long bed trucks? Just chopping off the ends of the framerails isn't going to help make the fenders fit. That's the reason you need to take a chunk out of the center of the frame, not the ends, when converting to short box.

 

Well I plan on moving the fenders back to compensate for the axle.

I have mocked it up and it doesnt look that bad. I plan on making some new running boards so this wll make the rearward axle look less obvious IMO.

I considered cutting the chassis, but I dont have a good enough welder for chassis welding here at home. Not to mention all the other stuff that goes along with shortening a chassis.

Ideally I would like to find an long bed someday and simply change the truck back to an long box truck. Adding the rear chassis section back on will be easy enough and not as structual.

 

If I read correctly you're going with 4.5" between bottom of box and frame? Would that be a little excessive? Also, I know my stock short bed on my F1 has only about 2" (roughly) clearance between the stake pockets and rear fender. Will your rear wheels centre in the fender opening ?

I believe the crossmembers for the box are 1 1/2" deep, and bolt to the top of the frame. The bed boards sit on top of that.

 

Yeah, but the top of the frame is not flat back there, it arches up over the wheels. The problem I believe he's having is that his cross members are no longer sitting at the correct positions relative to those frame humps. If I have my perspecitve glasses on right, the back cross member is now probably sitting on the peak of the hump instead of the back side bottom of it and thus the bed is up too high.

The bottom surfaces of your bed boards should just be touching (or be 1/8 or so inches above) the top crown of that hump.

In order to correct this you need to remove the cross members from the box and bolt them in the correct positions on the frame - either side of that hump, then rebolt them to the box after you get it positioned.

On the F1 this frame height is 2."

This is a 51/5 frame box but it's the same hump wise.





It also appears from your pictures that you are missing the cross member that goes between the truck frame and bed front wall - that's your other 2 inches. In the picture below the bed front wall is missing and you can see the crossmember, frame, and back of the cab.

 

Just thinking out loud; if the mockup allowed rear fender placement where you want it, will the running boards meet up to the front fenders and the supports ? From your pictures it looks like your rear fenders will be higher than the front, givng you fitment issues unless you get the box elevation down near the frame at the front. If this is the case then you may have to "raise" the box floor to clear the frame "hump" at the rear.

Tom

 

Well, sigh, I think you two (Wayne and Tom) are right about those fenders and the stake pockets.

He's going to adjust for 7-8 inches of wheel base with 2 inches of space between the back of the fender and the stake pocket. I guess he could put the fenders on backwards!

I'll be really interested to see how this turns out!

 

Running boards will be custom made to match up where ever the rear fenders end up!

My bed has no crossmembers at the moment as they were all bent or rotted.

The rear of the bed is sitting on the stock mounts for the 60's truck it came off of! Should these be reomved so I can lower the rear of the box?


Here is some pics of a quick mock up of where the fenders will go as far as front to back location. I will be lowering the fenders to line up with the fronts. They obviously need to lowered but the bolts from the old fender locations worked as a good mock up locator.




Those numbers sound correct for the way the donor bed was set up when I got it! However with the long bed chassis the lines seem different, or it could be the rear mounts from the 60's bed.

 

Have you placed 2 x 4's on their side across the frame at rear and towards the front to see what the height looks like ? You'd have to slide the bed back to clear those rear brackets. The 2 x 4' would simulate the crossmenbers, you could place 1x4 's length wise for the bed sides to rest on which would give you close to stock height starting point.

My concern would be the running boards, not length but height. If you place the rear fenders higher than the front, the running boards won't line up with them.

 

I think since you are already deviating from stock in terms of axle placement (relative to the short bed) and fender location, I would just make the bed fit where it will. Then drill new holes for the fenders, fill the old ones, and line the running boards up the way they should be.

Dave

 

Ok... I think cutting those rear brackets off might help me get the bed in a better position. I hadn't really thought about using 2x4's as crossmembers. Good idea

I have the heights from the stock crossmembers so I guess I will try to rip some 2x's to the same dimensions for mock up.



Yes the fenders will get new holes to place them in the correct orientation for the custom running boards to line up and so they are no higher than the front fenders.

 

In that case, just bracket the bed so that it sits level and then mount the fenders so they are at the correct level to line up with the front ones.

IMHO, seems like a lot of work (custom running boards, altering the bed and fenders...) for something that is only temporary until you can find a long bed to put on it.

Dave

 

Well I dont know about Kansas but here in Rhode Island, finding a 1956 anything is super difficult. I have had the truck for a couple years while I gathered parts and moved along on other projects. In all my searching I have yet to find even a rotted long bed locallly or a set of doors that were worth saving, in retrospect I could have used some of the parts from other doors I have seen as my current doors have no glass.

I have contemplated making my own sides but duplicating the rounded tops is inpossible with the equipment I have availabe to me. I got the short bed for the bubble( free ) so I feel modding it to work suits me fine.
As for the running boards, I would have to make them either way. Short bed or long bed as I have no long bed boards to use. So even if I put a long bed on down the road I will still be able to re-use the custom running boards as the wheel base and rear fender location will be farily close.

If I won the lottery I would just order everthing I need!

 

The original box on my F1 was shot; so I had bed sides broke to the stock dimensions. There is a lot of labor involved to fasten the top rail to the sides but it is an option. I think both sides cost $ 150.00 total, then tubing and aftermarket stake pockets.

I plan on building a utility trailer / camper using the top rails I scavenged from the original box. I'll get sides broke to my dimensions, and for this will probably spot weld the tops to the new sides. (Envison the top slid inside the box side then spot welded)

Tom

 

Well, I think most of us can relate to that sentiment. Maybe. Then again, it's been a lot of fun learning what I have so far in the process of building my truck, and I have a ways to go. It doesn't necessarily take a lot of tools to do some of the stuff. Probably the most important tool you need is patience. If you are like me, you have more time than money. And if you aren't after something that looks 100% original, you can get pretty close using tubing and some sheet. You can even fold the sheet for the sides without anything fancy. A 2x, some angle, and some clamps can be used with a slapper or even a block of wood to slowly fold the edge of a piece of sheetmetal over.

I'm not trying to discourage you from doing what you are doing. Just saying, like I did in another thread, that the inability to find readily available parts shouldn't keep us from building the trucks we want to build.

Dave