Re: '72 C3500 GMC flatbed project
 

Today's update:

PTO Controls installed. I used bezels from factory switches so they *kinda* look like they belong, but the lead on the cables is such that they won't quite sit square to the cluster... oh well.
http://i138.photobucket.com/albums/q...psaa7a48c0.jpg

Stripped out all the old hardware
http://i138.photobucket.com/albums/q...ps1bdb5e76.jpg

Trimmed and routed some planks to fit
http://i138.photobucket.com/albums/q...pscfd1fa04.jpg

Did some test fitting
http://i138.photobucket.com/albums/q...pse904daac.jpg

And got it all decked out
http://i138.photobucket.com/albums/q...psd833c096.jpg
http://i138.photobucket.com/albums/q...psa6527a7c.jpg

I still haven't installed any of the middle hardware, and the ends are only on finger tight, but I ran out of time and daylight. Project for another day.

Re: '72 C3500 GMC flatbed project
 

Better shots. It's starting to look like a real truck again!
http://i138.photobucket.com/albums/q...ps92230db6.jpg
http://i138.photobucket.com/albums/q...ps5d4c04bc.jpg

Re: '72 C3500 GMC flatbed project
 

Update time!

My rear view mirror has fallen off repeatedly, so I went to the '71 style
http://i138.photobucket.com/albums/q...ps62bcb5ec.jpg

Manufactured new PT frame spacer blocks
http://i138.photobucket.com/albums/q...pscbcf9cad.jpg
http://i138.photobucket.com/albums/q...ps4821150c.jpg

And I didn't like the open rear frame look, so I threw together a quick frame cap / bumper this afternoon
http://i138.photobucket.com/albums/q...psf46f56cb.jpg
http://i138.photobucket.com/albums/q...psbae3300a.jpg

And I got loaded up for the local truck show tomorrow :metal::gmc2::chevy:
http://i138.photobucket.com/albums/q...psf2ee53d4.jpg

Re: '72 C3500 GMC flatbed project
 

That's an awesome flatbed. Don't let it sit, it needs to be worked everyday!
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Re: '72 C3500 GMC flatbed project
 

Thank you! I intend to put it to work very soon.

Just one crummy shot of my junk from the show today
http://i138.photobucket.com/albums/q...psacbabae8.jpg

In other news, I finished shortening the rear wiring harness and re-taped it... not much to show, but that was the idea ;)

Re: '72 C3500 GMC flatbed project
 

Hard at work today, hauling scrap.

In fact, hauling the truck that donated all the parts to build it :metal:
http://i138.photobucket.com/albums/q...ps756d0c5f.jpg

Re: '72 C3500 GMC flatbed project
 

Just a couple quick shots of Red showing off his stuff :metal:
http://i138.photobucket.com/albums/q...ps9518482c.jpg
http://i138.photobucket.com/albums/q...ps0f613f2a.jpg

Re: '72 C3500 GMC flatbed project
 

Not much to report. Got some sideboards made up for the bed, I have to finish the gates and latches in the morning.
http://i138.photobucket.com/albums/q...ps4beda67e.jpg
http://i138.photobucket.com/albums/q...psbd52f993.jpg

Other than that, I have a semi-major front end overhaul coming in the next few weeks to get past state inspection for the year.

Re: '72 C3500 GMC flatbed project
 

Finished up the gates yesterday

http://i138.photobucket.com/albums/q...ps07e32f92.jpg
http://i138.photobucket.com/albums/q...ps1df54a2c.jpg
http://i138.photobucket.com/albums/q...ps1b07ce65.jpg
http://i138.photobucket.com/albums/q...pscfc5ff8b.jpg
http://i138.photobucket.com/albums/q...pseb111c01.jpg
http://i138.photobucket.com/albums/q...ps1117740f.jpg

Re: '72 C3500 GMC flatbed project
 

Not much to report at all with this truck, other than I found my scary engine rattle - turned out to be a loose alternator belt allowing the fan to slip. Now that it's not, I definitely know I need to get a clutch fan!

Truck has been working hard. I just went on a 160 mile trip to pick up an air compressor, cruising between 60 and 70 most of the way, and was pleasantly surprised to get 12.2 MPG average for the trip. That's better than my 307 1/2 ton!

http://i138.photobucket.com/albums/q...ps52b21fab.jpg

http://i138.photobucket.com/albums/q...ps668d740d.jpg
http://i138.photobucket.com/albums/q...psea7804ba.jpg
http://i138.photobucket.com/albums/q...ps703ff765.jpg

Re: '72 C3500 GMC flatbed project
 

Like!

Nice job. Nothing beats an old dually -- back for 4 more decades of work. And then it will still be askin' "more please"!

I made a set of wooden "stake bed" sides for my rollback so it can do more than haul cars as well. Makes for a rather large tilt-bed dump.

Cool to see you restore the SM465 PTO setup. I ended up using a Muncie dual belt-drive for mine. Electric clutch. But prevents me from easily adding A/C. Also made for some interesting fab work to get the correct clutch fan spacing.

Re: '72 C3500 GMC flatbed project
 

Well thank you! Somehow, in my mind, an old truck has to have a PTO. It was a tough call, the '67 I pulled the parts from had floor mounted levers to control the PTO, but I just couldn't bring myself to hack into a perfect factory floorpan.

I've never seen a Muncie belt driven hydraulic unit for a bed before, that's interesting! It's fairly common to see that sort of set-up on period snowplows, but they're basically just a second power steering pump. Is the Muncie set-up some kind of heavier duty pump?

Re: '72 C3500 GMC flatbed project
 

I love the bed ,I wish I could find one that size for my 72 0ne ton.

Re: '72 C3500 GMC flatbed project
 

At one time, I never saw a HD belt-drive PTO either, but here it is:

http://www.munciepower.com/products/...&back=Products

Mine is an older 4-5 GPM PH series unit. Works great to operate the bed. I have a large hydraulic recovery tank, so there is plenty of extra fluid for the large rams on my setup. The bed setup is fairly new, but the 40 year-old hydraulic winch (possible original) is SOOOOO slow. I can't bring myself to replace it because it can pull a house.

Re: '72 C3500 GMC flatbed project
 

They're out there, it's a factory setup, about 90" wide and 110" long. I wish I could find a cleaner one here in New England to replace a couple of the cross supports!

Learn something new every day. That looks a lot like they took their standard small volume pump and mounted it to an A/C clutch.

I actually want to add a recovery tank to my setup, as right now I just have the ram itself as a reservoir and it doesn't work terribly well when it's cold because there isn't much gravity pressure to feed that cold fluid down to the pump.

Re: '72 C3500 GMC flatbed project
 

I am looking foreword to seeing the 4 wd conversion !

Re: '72 C3500 GMC flatbed project
 

A few donor photos - '87 Sierra V3500, more or less stock and supposedly 50k original miles. Not original engine, but has d60 front, 14 bolt FF rear, SM465 and NP205 combo. Works for me!

http://i138.photobucket.com/albums/q...ps7ed58d31.jpg
http://i138.photobucket.com/albums/q...ps4c600653.jpg
http://i138.photobucket.com/albums/q...psafbf311c.jpg
http://i138.photobucket.com/albums/q...ps269a2f62.jpg

fabulous cab corner installation :lol:
http://i138.photobucket.com/albums/q...ps6af228d8.jpg
http://i138.photobucket.com/albums/q...ps205c8d82.jpg

Overall, should be a great parts source. And a good trailer test, I towed it home 110 miles with Red :gmc2:

Re: '72 C3500 GMC flatbed project
 

Very cool I'm in. :metal:

I can't wait to see it as a 4x4...

Re: '72 C3500 GMC flatbed project
 

Warm weather is finally coming! :gmc2:

Got the cab off my parts truck this weekend. Next weekend I'm going to get the dump body and exhaust off, and pull spring hangars etc so I can blast and paint them. Getting close!

http://i138.photobucket.com/albums/q...psc142b196.jpg

Re: '72 C3500 GMC flatbed project
 

What is your plan of attack to put the D60 in? I have seen a couple of trucks converted but they never put up a thread on it. Looking forward to this. My father in law has a 67 GMC C35 that he bought new that I would love to do this to. I am trying to dwindle down some of the trucks at my house so I can try and get the 67 over here and have a place to keep it out of the weather.

Re: '72 C3500 GMC flatbed project
 

So I'm a little behind schedule on this project :lol:

Anyways, based on the measurements I've taken it's actually going to be fairly simple. The front spring hangars line up with the original core support mounts on my '72, and that sets the wheel properly in the fender opening. Interestingly enough, it also keeps the engine in the forward mounting position (which is great, because in my K10 trying to work on the distributor is MISERABLE)

I am going to lift the front, engine, and trans/t-case cross members out of the V3500 frame and drop them into the C3500 frame after I remove the 2wd cross member - everything is close to lining up as is, there are a few holes I need to adjust.

Either way, I am planning to take a LOT of photos and do a write-up on the swap as I go. I'm also going to hydroboost and updating the brakes while I'm in there. This truck is going to be sweet! Just have a lot of rivets to cut in the meantime

Re: '72 C3500 GMC flatbed project
 

More dis-assembly of my parts truck today - I was able to get much better comparative measurements between the two trucks:

1. The core support mounts on the '87 are one full bracket width further forward than on the '72 - I am going to have some trimming and welding to do to make them line up perfectly, but it actually works out better than I had thought as I do not have to remove my original core support mounts. This centers the front axle in the wheel opening

2. The engine does have to move - nominally it will move back 2", so midway between the front and rear mount positions. That said, it looks like there is enough adjustment in the engine mounts to reduce that to about 1.5" back. Hopefully that's not enough to require modifying the floor pan for the shifter. The motor mount brackets are a direct bolt on to the frame; the holes are in the same location and spacing. This gives me a good, solid reference point on the '72 frame for mounting the '87 parts.

3. The shackle bushing for the front spring lands directly where the parking brake cable presently passes into the frame. I am planning to use the '87 style parking brake cables to alleviate some PTO interference issues I've run into, which eliminates the need for the raised part where the cable enters the frame. I'm going to have to either pound that flat, or possibly cut it out and weld in a new piece of flat metal.

So long as it doesn't rain, I will make more progress tomorrow. I have the trans, T-case, and driveshafts all out of the donor truck, and I'm about halfway through pulling the front cross members.

Re: '72 C3500 GMC flatbed project
 

Donor truck is finally completely broken down. This weekend I will be sandblasting and painting all the bracket and starting to break down the C3500.

I have also discovered something interesting. The front spring hangers from the V3500 are, in fact, swappable - meaning I can install the left on the right. This lines up with the original frame mounts on the '72 perfectly.

I've also found that the rear spring hangars match up with one pair of holes on the '72, so I have good reference points at both ends to set my suspension from.

Other than that, I'm also working on installing the '87 Hydroboost setup on the '72 - based on some comparison today, I should be able to modify the hydroboost base plate to mount directly to the firewall in the '72, which is excellent news. I will have to either modify the pedal or the pushrod, though, as the hydroboost pushrod is some 2-3" shorter. We shall see but I suspect I'll modify the pushrod, the geometry for the pedal doesn't lend itself to modifying the connection point.

I promise to have some pictures soon!

Re: '72 C3500 GMC flatbed project
 

Okay, a few photos. I'm going to be doing a lot of cleaning / painting tomorrow.

Driveline - SM465 / NP205, directly as it came out of the truck
http://i138.photobucket.com/albums/q...ps9af40415.jpg

Front suspension parts. Front cross-member with sway bar mounts, engine cross member and mount pads, front and rear spring hangars, brake line brackets, upper shock braces, bump stop mounts.
http://i138.photobucket.com/albums/q...ps24298678.jpg

Rear suspension. Including trans cross-member and transfer case skidplate, front and rear spring hangars, bump stop mounts, upper shock mounts, and parking brake cable mounts.
http://i138.photobucket.com/albums/q...psf0d6d5db.jpg

Just a fun little visual, all the parts laid out as they came from the frame
http://i138.photobucket.com/albums/q...ps483d6fce.jpg

The rear hangars for the front springs land directly where the parking brake cable passes into the frame on a 2WD 67-72 truck. I've pulled all of the pieces from the V3500 parking brake, which runs under the driver's frame rail rather than through the frame, which solves the problem. I will have to weld a mounting tab to the driver's front cab mount to hold the end of the cable.

Re: '72 C3500 GMC flatbed project
 

Cool! I am very interested in this build. Looking forward to more.