72 C20 "Old Mustard"

[Mustard72]

My wife and daughter have started getting into horses, so they'll need a reliable truck to pull around a horse trailer with. This has been the opportunity I've been waiting for to get some work done on "Old Mustard", my 72 C20 that I've had since I was 16 in 1986. I'm stoked.


Here's Old Mustard...

[DustinB]

Sweet! I also got my 72 c20 when I was 16. But that was this year. hahaha I sure know mine pulls trailers real well so far.
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[Mustard72]

The objective at this point is to replace the cab floor (pretty rotten, especially under the gas tank), replace the 3speed with a TH350 trans, and install a trailer hitch to use instead of the rusty old step bumper. I was trying to figure out how to put the floor in (in pieces) without removing the cab, but I'm now planning on just removing the cab like everybody else apparently does. I pulled the seat, gas tank, etc. out a few weeks ago. This weekend, I removed the front fenders, inner fenders, cowl, etc. in prep for cab removal. I know that a majority of vehicles that start getting torn down like this never get back together, so I've got to keep moving with this project and get it done. It helps to have a purpose (pulling a horse trailer) and to have the knowledge that a bunch of people are monitoring your progress.

[Mustard72]

I've seen your thread, Dustin. Looks like a nice truck you've got there, especially for that price. Being from down South, its in much nicer shape than mine, which has some serious rust. As soon as I get a little bit of time, I'll post more pics, and you'll be even more pleased with your blue one.

[DustinB]

Thank you, yeah that is one of my favorite things about living out here in the super dry west, no rust. Haha I do like that yellow of your truck though. Not something you see every day. Hahah
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[Mustard72]

Yeah, I like the color, too. Eventually we'll get rid of the "ketchup" color on the bed. A girl that lived down the street from us back in the day in high school called the truck "Old Mustard" (had a yellow bed back then). My brother and I kept trying to call it tougher sounding names, but none of them stuck and "Old Mustard" did.

Below are pics of what happens when the parking spot for the truck is under a tree. We'd get leaf shreds blowing out the defrosters every once in a while.

[Mustard72]

Oops, here they are...

[Mustard72]

I haven't seen these mirrors anywhere else on this forum. I'm guessing they might be aftermarket. Anybody recognize them?

[Mustard72]

...and some more progress shots from the last few days. Ended up grinding off the heads of at least half of the inner fender to outer fender bolts, as the nuts inside the fenders started spinning. Those apparently aren't welded on, are they?

Whatever the case, I'm getting closer to being able to pull the cab. I removed the radiator and radiator support so I can replace the mounts under the support. I was only planning to do as little as possible to get the floor repaired and get her back on the road, but I can see now that there will be some cleaning and painting going on, too. Looking for some fenders/inner fenders, as well. Dang scope creap...

[DustinB]

Haha that's about how it always works isn't it? The more you want to
Change a nickname the more it
Sticks. and man that's a whole lotta
Leafs.. Hahah
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[Mustard72]

Wow. All I've got done on Mustard so far this week was to remove the brake master cylinder and booster. I gave our two drivers (Taurus wagon aka Mommy's Red Car and the blilver Kia Sedona aka the Man Van) a once over in the other stall of the two car garage with such pampering touches as overdue oil changes, tire rotations, etc. Unfortunately, the Man Van needs a drivers side tie rod end, which will put off progress on Mustard even more.

Although I might have a lead on some front fenders in better shape than mine, so that's a good thing

[Mustard72]

Parts store didn't have the tie rod end for the Man Van, so I ended up with some time for Mustard this afternoon. Pretty much have it ready to be braced up and picked off the frame at this point. Pulled the steering column, speedo cable, tach wiring and tach, floor shifter handle, clutch linkage (not going back in), water temp thermocouple wire/gauge, crappy, brittle plastic tubing for oil pressure gauge (probably only had a few miles left on it the way it desintegrated when I touched it). Now I gotta come up with a spreader for the cherry picker, brace the door openings and brace across the cab, and disconnect what's left of the mounts (might be blue wrench time).

[Mustard72]

Here's what the floor under the gas tank looked like when I removed the tank. I'd like to blame the PO for this work, but I can't. We did this repair back in HS to keep her on the road. Not good work, but remember, Mustard was just another old truck back then, only 15 years old or so. Sort of like working on a rusted out late 90s pickup now.

[Mustard72]

Yep, that was an expert application of bondo, roofing tar, and window screen covering up the new "structure" we had to hold the cab together and bolt seatbelts too (safety first, after all). I was dreading tearing it all out, but the tar was pretty dried up and it all came out rather easily. Good golly, there really isn't much holding the cab on, is there?

[Mustard72]

OK. Got the cab popped off the other day. Here are some shots of the process. Made a spreader out of two old 2x4s with some plywood screwed to the tops at each end to hold them together and act as stops should the cab want to slide one way or the other. Removed the chain from the cherry picker and attached the spreader to the lifting arm with an old tire iron (didn't have the right size bolt...). Worked pretty dang good, I guess.

[Mustard72]

You can see in the shot above of the rear of the cab that I might be in trouble when it comes time to weld the new floor in, as the bottom of the back panel of the cab is in pretty rough shape. Nothing a little extra sheet metal welded in won't fix, I imagine. We'll see how things go.

Here's a shot of the shop helpers for the day.

[Mustard72]

...And, since I had it this far apart, I veered off track and yanked the greasy blob of an engine, with the plan to get it cleaned up, change some gaskets, shoot a coat of paint on it, clean up the frame and maybe get a coat of paint on it, too. It's a lot of work so my wife and daughter can pull horse trailers around, but they're worth it, and I'm having a blast with this.

Just hope I can get it all back together...

[Mustard72]

Once I had the cab on it's back, I ground off the welds connecting the "floor" to the back of the cab, then proceeded to find all of the spot welds in the floor/firewall joint. I think there's just shy of a bazillion of the dang things. I'm also thinking that the spot weld guy back in '72 didn't have any sort of jig to use to place the things, as they were sort of all over the place on the flange. Many of them were right close to the bottom (or top, depending on which way the cab is sitting, I guess) of the flange. I ended up being too cheap to spend the $5 for a spot weld cutter from Harbor Freight (would have cost more to ship it here than the cost of the cutter itself), so I just drilled out the spot welds using two smaller diameter bits and then the 3/8 bit. With some of the spot welds that were close to the cab floor, I ended up removing some floor material, too, but it seemed to be almost unavoidable, and not that big of a concern at this point anyway. I didn't get the floor all the way out, however, before I ran out of time for the day, so that'll have to wait. Even with the spot welds theoretically drilled out, there is still some areas welded together which will obviously take some more work. I used a cutoff wheel and made a cut a few inches down (or back if it were sitting normally) from the flange all the way across, but I haven't gone through the two major front to back ribs (can't remember exactly what they're called), and I didn't get all the way through one of the sheets scabbed in under the drivers side footwell. That, too, will wait for another day.

[Rochlow]

I'm not sure if you have or not.. But I would brace the hell out of that cab before you consider pulling that floor out.

[Mustard72]

It's braced, but not as heavily as most of the others I've seen on here. I tried to keep the bracing towards the bottoms of the door openings and then put a brace across between the two door braces. The floor is out now (need to update the pictures here), so it's all the bracing, now, and it seems to be holding well, actually.

[67c10rustbuket]

Dang Mr. Mustard, that was one rusty cab! You made the right choice on the full floor replacement. Kinda wish I did myself but mine was nowhere near that bad. Great job on the truck!
It has been a long time but actually half of me is from Wisconsin, Menomonie to be exact. You have a great start on this project and I can't wait to see the finished cab repairs. Keep up the great work man! I'll be watching you.

[Mustard72]

Thanks, Dan. Yah, it's pretty rusty. But I know of guys that rebuilt obscure pre-war trucks that had trees growing up through them, so I use that type of thing for inspiration when working on this "relatively new" truck that has all of this aftermarket support available for it. Still spend quite a bit of time just standing there staring at it figuring out what to do next, though

Hoping to get some more time out in the garage this afternoon. I'll try to get the pics updated some time this weekend.

[Mustard72]

Time for catching up on posting progress info. I managed to get the floor out a few weeks ago. I did as I've seen elsewhere on this site and cut the floor apart a few inches behind the firewall/floor seem, then chiseled the seam apart, which still needed to be done even though the spot welds were drilled out.

[Mustard72]

I apologize for the quality of some of these pics, along with the fact that I forgot to rotate them before attaching them to the post.

I went down the path of replacing both of the cab corners and bottoms of the rear pillars before getting the floor in. This proved to be a bit of a bad idea, as getting the flooor in the right place with the new cab corner in place proved to be a bit problematic. The door just didn't fit right, etc. The cab corner (LMC) didn't really fit that well, either, without a little bit of bending into shape to better match the curve of hte back of the original cab. Nonetheless, here are pics of the wasted effort...

[sduckworth13]

Looks like it will be a nice truck when your done, I notice that the cab roof looks pretty good above the visors. Thats a plus.