Seapine - 1972 F350 flatbed build

[SeapineF37]

so, got a few engine items done.

new edelbrock performer intake went on to fix the terrible oil leak at the back of the block (the whole rear of the old intake between the intake and motor had NO seal. was a big reason for oil all over the bellhousing and bad idle / vacuum problem.

also put a new holley 4160 elec choke carb on plus new points and wires and she's running pretty good! did the work at a friends diesel repair shop and he tested compression while it was there... +/- 0% alross all 8 cyl

adjusted the timing with the new setup too. was running best at 6* 700rpm idle no vac / 40* @ 2000rpm w vac. seemed a little high to me but was running good there. is that normal?

anyway, also here are some pictures of the start of work on the bed. plan is to shorten it about 18" by cutting out a section and welding the rear end of the bed (with curved corners and stake pockets) back on. removing allthe rotted wood left underneath. welding in a new underframe with a strong gooseneck ball hidden hitch. and building wooden stake rails...

here is the truck at my friend curts. he's got skills and more tools than at my house. plus i enjoy getting to do projects with him. he loves working on trucks too (has some killer WWII vehicle oprojects going) and teamwork helps in this department...


(loving the new halogen headlights)

marked and cut off the rear end of the flatbed. notice the misc wood left and all the bad welding over the years to modified hitch mounts





next step is pull the bed, remove the wood, cut out the 18" section to shorten, and weld back together.

[Canonman67]

Looking good Seapine. You'll want to keep the relays even after you rewire since the switch becomes the weak link at that point.

[SeapineF37]

thanks canonman67.

Looking good Seapine. You'll want to keep the relays even after you rewire since the switch becomes the weak link at that point.

yep, planning on a good deal of upgrading to the wiring and will be installing a good relay bank. just some cheap relays temp wired in for now to get the headlights working...

bed came off so upgrades to it as well as cleaning up the rear half of the truck ensue!

pulled the bed with a chain hoist from an oak tree limb. classic stuff


can easily see now how they decked over the rotted wood flatbed a long time ago. time to strip all that out and put new crossmembers underneath.


also cut all the old welded up metal work off the end of the truck frame. left just enough frame rail behind the rearmost crossmember to mount a bed support and then attach the pending new rear bumper that i'm templating out of a stick of 8" channel.

next up sandblast and paint up the rear half of the truck and get the bed framing back together.

[Jacksdad]

Looking good
Life got in the way over here, and I haven't had a chance to do any work on Bessie. Tomorrow I'll try to find time to get back into finishing the roof. Looking forward to getting to the same point you're at with the chassis exposed and the cab closed off.
Keep the updates coming - it might just inspire me to get my butt in gear while we still have good weather.
It's rare to see a truck built much the same as I'm shooting for, so I have a couple of questions if you don't mind. How long will the bed be after you've shortened it? I have extensions welded on the end of my chassis rails to support the last part of the camper box, and if I kept them on I could stretch the bed to about 11 feet (although I probably won't).
How was your bed attached to the chassis? I'm torn between steel mounts supporting it at three points, wooden boards shaped to follow the frame rails, or a dump truck hinge type mount like Ranchero's.

[SeapineF37]

thanks jacksdad. yeah the life things happens plenty here too.

the bed was sitting on two long sticks of tubing that rested on small hollow "blocks" - just behind the cab and at the far back end of the frame rails. not particularly stout. you can see the chain wrapped around one of the square tubes in one picture from the previous post - the picture of the bed upside-down. i love ranchero's setup but no access to a dump frame. im welding in a gooseneck tow hitch that i will be making rather secure so larger tubing setu going back in w crossmembers and 3 half-inch plates to bolt into the fram in front middle and rear. frame mock up coming shortly so you can see what the heck im talking about

bed is about 7.5ft wide and 9.5ft long (92" x 110") and i'm cutting it down to about 92" long so it will actually be close to square when im done...

here are some photos of the truck frame work. all sandblasted and painted up matte "hot rod" black epoxy. stuff is really durable.


hot and sandy. its florida summer.


really happy with how it turned out. threw some of he old lights back on w temp wiring so i can keep driving it.

[Jacksdad]

Thanks for the reply
Ooh, that's a purty chassis. That epoxy paint looks great on there.

[hfdco4]

Very nice job.

[Ranchero50]

Looks nice but I'll be honest and say I really love my 10'6" bed. I'd even be happy with a 12' bed if the truck had a tighter turning radius. If I were to run a short bed I'd move the axle forward to a standard 8' bed length. Looks wonky as a long wheel base short bed truck.

Oh yeah, go ahead and make the pivot points for it to dump. You know you'll want it to eventually and will only need the hydraulic installed.

[Jacksdad]

Oh yeah, go ahead and make the pivot points for it to dump. You know you'll want it to eventually and will only need the hydraulic installed.

[SeapineF37]

ha thanks hfdco4 and jacksdad and yes rancho i hear ya.

i do enjoy the functionality of a long bed but two biggest uses driving the build are daily drivability (which makes a short bed a nice feature) and towing for a gooseneck trailer (which requires a long wheelbase). the gooseneck trailer has a full loading upper deck on the neck meaning the hitch has to be at least 51"+ inches behind the headache rack to allow the trailer to clear the fron of the bed on full 90* turn, plus the hitch needs to be forward of the rear axle centerline for best load handling (i'm planning 1.5"-2" in front of the axle). yes this means the truck may be a bit unique in its bed configuration and the long wheelbase w short(er) bed may appear a bit wonky to some but thats what works best for me so will see how this idea turns out

first, some work on the new rear bumper. a both more like a towing hitch bumper my idea is to leave it tucked up under the bed a bit allowing for tight backing to loading ramps etc. going to weld in the reciever hitch and use truck/trailer style brake/tail and reverse lights.






on the new bed crossmember supports, the entire underdeck is being gutted. laying out the new heavier duty tubes which will be the framework for the 1" plate mount for the gooseneck ball. sitting on supports in the front and just behind the rear hanger crossmember, these rails will get 1/2" plate gussets welded that will extend down and be bolted into the side of the frame in the front, middle, and rear on both sides.

[Jacksdad]

Making some progress there, Seapine - I'm watching this with great interest because in all the years I've owned mine, I've never got that good of a look at the chassis. Height-wise, where are you going to have the bed positioned in relation to the "bump"? For no other reason than aesthetics (I know - makes no sense...), I'm shooting for higher rather than lower.
Hope you don't mind, but I'm saving your pics as reference material

[Ranchero50]

I wonder why someone took off the helper springs? Just checked mine and it has 9 main leafs and 4 helpers. The separate groups allows the suspension to work better unloaded.

[SeapineF37]

Making some progress there, Seapine - I'm watching this with great interest because in all the years I've owned mine, I've never got that good of a look at the chassis. Height-wise, where are you going to have the bed positioned in relation to the "bump"? For no other reason than aesthetics (I know - makes no sense...), I'm shooting for higher rather than lower.
Hope you don't mind, but I'm saving your pics as reference material

thought a bunch about the bed height for both looks and functionality. looks like the bed will be fairly close to being in line with the bump for me. somewhere around 40" off the ground at the front of the bed unloaded and 42" at the rear due to rake unloaded. this should put the bed close to the lower part of the bump line and not cause too much visual awkwardness while also putting the gooseneck hitch at the height i want and keeping the bed high enough over the tire clearance while not being too high to conveniently load from the ground... a lot of factors. will see how it turns out.

I wonder why someone took off the helper springs? Just checked mine and it has 9 main leafs and 4 helpers. The separate groups allows the suspension to work better unloaded.

not really sure. realized it soon after i saw there was only one aux leaf spring bumper ( you can see the rear driver side one is the only one left attached to the frame in the previous picture). no idea why the helpers were removed on both sides but just the 9-spring main leaf packs are on the truck. must have been some effort as those aux ride bumpers are riveted to the frame and someone must have removed them but no sign of them existing at this point so must have been a long time ago? the u-bolts look original though and no spacer or cut helper pack so i was curious as well but no idea on an answer.

so got the rear bumper painted and the light housings too (all black was the look i was going for) bolted on and cut up the rear wiring to at least temp in the lights. so no more c-clamp brake lights

some progress photos of the underframe work for the bed. now you can see what i was talking about with the frame mounted supports. finalized the location of the main support tubes (distance from back of the cab) and drilled/bolted the front set of supports. spacers between long tube supports and frame are bolted to frame, and plates outboard of frame will be welded to support tubes and spacer tubes.






also used full plate over tubes plus double thick plate for the gooseneck ball will mount. old school specs for heavy duty agricultural hauling.






more work on the bed next and then will see how it all comes back together!

[Ranchero50]

That's a bummer that someone cut them off. I'd definitely get them reinstalled before loading it heavy. Mine come into play with @ 1k of stone on the back and my bed only weighs 500lbs with the hydro's.

[SeapineF37]

That's a bummer that someone cut them off. I'd definitely get them reinstalled before loading it heavy. Mine come into play with @ 1k of stone on the back and my bed only weighs 500lbs with the hydro's.

yep but seriously strange. other than the one aux spring bumper, i would swear the helpers just never existed on the truck. but have some thoughts on load testing and other spring helper options.

more updated on the bed rework...

cut the section out and cleaned out the rest of the old wood bed hidden under the diamond plate.


flipped the bed over and did the main rewelding of the rear section back onto the deck.




then back over again to weld back in the new crossmembers and cut out th hole for the gooseneck hitch plate access.




bolted and welded in th crossmembers to make them match up to the original designas best as possible.


some more welding and work on the access hole for the hidden hitch and then on to setting the bed back onto te support frame...