First square. 1980 GMC
 

Hey guys, I finally got this project home this Saturday. Bought it a week ago, but couldn't get it back here. I'll include pics at the end of the text

I have a bunch of questions because i picked this thing up really cheap and know it needs alot of work. I have no mechanical experience or fabricating. I've wanted a 73-87 since I was 15 so I went for it. I know I'm jumping in way over my head but I want to learn every single thing I can..

So it's pretty rough, bed is rusted through and damaged on the side. I suppose I can try to find another bed to put on it. I haven't got to get completely through the cab yet to see what the deal is there. The hood is obviously bent, but closes somewhat. I'll find another for it if I can. There is some weird wiring done I think, and i'll have to try to sort that out.

My biggest questions is where do i start?? It doesn't run.. supposedly needs new head gaskets. I don't think the carb was functioning right, so I just pulled it off tonight, with tons of pics of everything how it goes. Going to try to find out a model on it for maybe a rebuild if possible... all I can see on it now is Rochester Quadrajet.. So ill clean a bit and see if there is anything else written on it. Hmm there is the numbers 17080206 on it, a quick google search brought me to some pics and rebuild kits.

Well here are the pics, just an Imgur album. I can upload them right onto this post if y'all would prefer.

http://imgur.com/a/f7hBv

Re: First square. 1980 GMC
 

First order of business is to buy a repair manual... and get to know your local pick n pull, and craigslist...

Re: First square. 1980 GMC
 

Yeah i didn't even think about that even though I just got one for my dodge. From the vin, I'm pretty sure it came with a 305 and it has an older gm 350 in it right now.. or according to the valve covers and what the guy said haha.

Re: First square. 1980 GMC
 

Welcome to the forum! You'll find everything from A/C to Vacuum here and a lot of guys to ask questions from.
Does the VIN start CCL (350) or CCR (400)? I don't see an option for a 305 on my VIN spec sheet.

Re: First square. 1980 GMC
 

Check the block numbers, directly in front of ta passenger side head stamped on the block surface. That will tell you what it is Other than the hood, the body looks nice. One of the first things I would do that I noticed that needs to be undone is the fuel line. Truck came from the factory with steel line the whole way from pump to carb. I would put it back that way. As far as the head gaskets, check your compression before you do anything. Not terribly difficult.

Re: First square. 1980 GMC
 

Thanks! I've browsed these forums for years and saw N2TRUX's truck a few months back at a show 5 miles from my house. He's helped me out alot with looking back when i was 15 and now again at 20.

My VIN starts w/ TCG I'm pretty sure(don't have it on me right now) and the decoder i looked at said T = GMC C = conventional cab and G = 5.0L 2bbl.. however I think it has a 350 in it? I haven't looked up how to really tell, it says 350 on the valve covers and thats what he said was in it.

Okay, I'll look up how to check the compression and try it out this week.. I'll also find out which lines you're talking about. I wasn't lying when I said I literally know nothing at all lol

Re: First square. 1980 GMC
 

Welcome to the forums, from a fellow Texas guy, that does not live to far from you. The truck is a little rough around the edges, but that is how mine started to, to there is lots of hope for the old girl. Looks to me that the person before you bought a GM Target Master engine and did a swap, I would bet money that is not the original engine.

Re: First square. 1980 GMC
 

nice score,looks solid
I'd lube up the hood,that can happen when the hinges seize up,

Re: First square. 1980 GMC
 

Yeah he said it wasn't and the vin says it came w/ a 305 not 350. and thanks for the welcome! Cool to see members somewhat close.



Also to anyone reading this, when you try to start the truck, you have to have it in reverse... how can I fix this? I have the carb off and whatnot right now but I'd like to know why I have to go from park to reverse to get it to even attempt to start and maybe fix it before putting the carb back on after cleaning/rebuilding(if I can haha).

Re: First square. 1980 GMC
 

Here's the lines I'm talking about. As far as starting in reverse, your neutral safety switch needs adjusted. Its on the lower end of the column, on top.

Re: First square. 1980 GMC
 

Ah thanks. I'll see what I can do about switching that line back to what it should be and adjusting the neutral safety switch if I can find it =p. Also have to find out what all the wires under the hood go to. I think the green one that is electrical taped into the battery and runs up the fire wall was for an amp/subs.

There are also random wires in the interior that I am not sure about.

I took the seat and carpet out today, not so pretty.. but I think it's not all horrible(if we forget about the floorboards)

Re: First square. 1980 GMC
 

I pulled off the dash pad thingy today and it was filthy underneath it. I also pulled the paneling under the steering wheel to look at the wiring.. I have no clue what any of it is lol. Any ideas?

Sorry for bad pictures, they didn't look that blurry on my phone.
The first pic is the radio. I'd like to remove it, but I'm not sure how to go about doing that. Can i just remove all wires completely that are connected to it? without messing anything else up.

The 2nd pic is a clump of wires hanging down. I don't know how to deal with these.. the orange and blue ones were running to the back of the seat for speakers/subs I think.

Any suggestions? or can someone point me in the right way to getting that mess cleaned up.

Also, is there a way to check if gauges work w/o the truck being on? probably a stupid question

And one last thing this post.. Any suggestions on a good way to clean up the metal of the floor in the cab? its just dirty and greasy and has rat crap on it. Not sure on the best way to get that up.

Re: First square. 1980 GMC
 

Looks like the radio is held in by the two nuts on the tuner shafts and there looks like there is a silver metal strap from the back of the radio to the lower dash. There should be a plug on the back of the radio. That should get your radio out. As far as the floor, I would wire brush and then use some POR 15 paint on it.

Re: First square. 1980 GMC
 

If you have any rust that you need to deal with. I highly recommend that you do what I did for my floor. Put a wire brush head on a drill and clean up the floor. Then vacuum the debris out. For the rust, I used a product called Conquest. Not sure where you'd find it around there, because I bought mine from a boatyard. Conquest is really expensive, but you shouldn't need much. Pour it into a pint bucket, yogurt container, etc. Mix it up and apply with a paintbrush to the rust. When it's converting the rust, it should turn the rust black. Allow at least a day for it to dry. Then you can prepare to paint the floor.

Re: First square. 1980 GMC
 

Btw, I'm glad to see there's another young guy on here. I'm 21, and figuring my '84 out as I go as well.

Actually, from what I can tell, your floorboards don't look bad at all. Mine were rustier than that. And I have a golf ball sized rust hole just inside the driver's door on the vertical part of the hump the seat mounts to.

Re: First square. 1980 GMC
 

20 here, so just 1 year shy of you. I might try that out on the floorboard.. biggest problem though is the pictures don't really show that the floorboard has random pieces of sheet metal screwed on top of it. Which I'm kind of scared to take off because it's solid enough now and I can't move it to someone who could weld new stuff on until it's running.

I'm going to try to get it running and whatnot first, I'm just ripping the interior out right now because teardown/cleaning is somewhat free haha. I'm having to do it pretty slow for now because I spent a few grand on my 2010 dodge.

I think the wiring will be my biggest issue. There also seems to be trash all in the vent system which I'll try to clean out tomorrow, and maybe get some cleaning equipment.. brushes and whatnot later this week along w/ carb cleaner and rebuild kit.

I'll have plenty more questions for everyone by the end of the week.

Re: First square. 1980 GMC
 

If you need seatbelts, I have the shoulder belts with the plastic retractor covers. There are in excellent condition, just need to be riveted back together. And the driver's side warning buzzer works if that matters to you.

I also have an AM radio that works pretty well. Anything else I can do to help, let me know.

Re: First square. 1980 GMC
 

I'll definitely have some questions for you I'm sure! I took the driver's side seat belt off. I'm going to replace them because they look pretty worn.. I just don't really trust them. The bolt into the floor of the cab on the passenger side seems to be stuck, I didn't mess with it today though. Not quite sure how to get it out. It does a lot of popping when you turn it and it takes alot more force to turn than the driver's side did.

Watching videos on headgasket replacements right now just to see what I'm in for.

Re: First square. 1980 GMC
 

I experienced the same thing when I removed the seatbelts out of the 1972 I parted out.

Spray it with lots of penetrating oil. Tighten it back up, then out again. That way you can work it out without damaging the threads.

Re: First square. 1980 GMC
 

Sounds like a pretty good idea, I'll have to try that out.

Happen to have any suggestions as to where I should get a rebuild kit for the quadrajet I took off of it?

I've looked up a few threads on here, just wondering if you had any experience w/ them.

Re: First square. 1980 GMC
 

I have yet to rebuild my Q-jet, but when my dad rebuilt the carb on our International Scout, he went to Mike's Carburetor Parts for the rebuild kit.
He's located between Seattle and Portland. His kits aren't the cheapest, but the service is unbeatable, and there are videos and demos on the website.

If all you care about is price, NAPA should have the kit you need. First, I suggest you get the numbers off your carb, and look them up on Mike's to identify the kit you need.

Here's the website: http://www.carburetor-parts.com/

Re: First square. 1980 GMC
 

Do you have the number on your carb handy?

Re: First square. 1980 GMC
 

Never mind, I saw the numbers on your first post. I'm not 100% (hopefully someone can confirm this), but I believe this is the kit you need:

http://www.carburetor-parts.com/Roch...Kit_p_742.html

Re: First square. 1980 GMC
 

[QUOTE=Mayhem.Evol;6641627]
The 2nd pic is a clump of wires hanging down. I don't know how to deal with these.. the orange and blue ones were running to the back of the seat for speakers/subs I think.

Those all look like speaker/stereo wires. I would take the stereo out, it should have a plug behind it with the wires...

Re: First square. 1980 GMC
 

Thanks! I'll check that out tonight

When I wire brush the floor, should I use some sort of chemical with it to help or just straight brush to metal?

ah I'll see what I can do about it then. I wasn't sure if they'd run right to the radio or what and didn't wanna start pulling haha

Re: First square. 1980 GMC
 

I can't seem to edit my post, I guess there is a time limit on it.. so sorry for the double!

Anyone have some recommendations for an engine stand? I did a search but alot of the links were outdated, so they didn't work anymore.

Re: First square. 1980 GMC
 

There is a time limit to edit posts.....

Engine stands are pretty common, just make sure you get one that allows you to rotate the engine.

Re: First square. 1980 GMC
 

I should get one with the U shape at the bottom and not a T though right?
Like this http://www.summitracing.com/parts/sum-918014/overview/

Re: First square. 1980 GMC
 

Yes, I would not buy one with a T.

Re: First square. 1980 GMC
 

If you have a harbor Freight nearby, you can probably get one fairly inexpensive. If you plan on using infrequently they work fine.

Re: First square. 1980 GMC
 

You don't need a chemical to wire brush. Just try to get the floor as clean as possible first (vacuum up the dust and crap). Then just brush away. For now, you only need to brush up the rust, them hit it with a converter (like Conquest). Don't worry about the painted part of the floor until you're ready to repaint it.

Re: First square. 1980 GMC
 

I think there may be one near houston. I'll check and see. Thanks for the advice

ah, alright. I may put off the floor for a while and just try to get it running and whatnot first. So I'll just do cleaning and wait to strip it down.

Gonna order that rebuild kit and a book on it today. Pick up some carb cleaner or something today/tomorrow. Any suggestions on that? I've never cleaned a carb before. Will just any work fine? I'm guessing I'll want to get enough to soak it and not just the spray cans

Re: First square. 1980 GMC
 

While soaking has its advantages, so does the spray cans, with the straw. The soaking loosens stuff up and the spray blasts it away. Just wear some safety glasses. And make sure you get some good quality stuff. I have used some in the past that wouldn't clean a fart off of a chair in a windstorm. Make sure you clean the small passages with the straw too. Take your time and follow the directions and get your float and such set right. You will be fine.

Re: First square. 1980 GMC
 

I grabbed a spray can and some wire brushes today. It worked pretty well. I just need to get some more of it tomorrow. I wasn't sure how well it'd work so I only got 1 can. My rebuild kit and book were ordered today so I've got a few days to get it all cleaned up nicely.

Re: First square. 1980 GMC
 

Well.. I got the carb rebuilt and back on. decided to try to fire it up.. it didnt go well. But not because of the carb, I don't think it even got to do anything.

The truck cranks really really slow if more than just a second of trying, but a few times it tried for quite a while.
Do I need more battery? I didn't know what I needed so i just had a guy look me one up at advanced auto parts and have that.
Maybe the starter is bad? or just some bad wiring?

Then I tried a bit more just before I was about to give up for the night and smelled burning rubber and smoke starting to come out of the hood so I popped the hood and the little black wire coming off of the bigger cable for the negative side had melted and has completely exposed wire..

and the positive has some ghetto rigged cable into it, circled in the pic.. It runs to the firewall and fastens under a bolt. Can't get any better pics cause it is dark, but I think the green wire must be connected otherwise it won't try to start. I drew a red box around it, it's barely visible though

Re: First square. 1980 GMC
 

I also noticed that the dash backlighting and radio go out and the headlights were dimming when it tried to start. I read online that this could mean starter problems.. Any tests or whatnot I could do?

And as i said before, you have to have it in reverse to try to start it.. So maybe I should trouble shoot the whole ignition system/wiring before trying to start it anymore.

Re: First square. 1980 GMC
 

First pull the Battery and give it a full charge. Then have it load tested. Autozone or Advance should be able to handle that. Then if that tests OK then move to the starter. Pull it an AZ or ADV can test them too. Also at every terminal you take off, clean it. Those wire brushes you bought for the carb will work fine.

Re: First square. 1980 GMC
 

Hmm, okay. I'll have the battery tested sometime this week if I can.

About the wire I burned up Where can i find a replacement? It's a little black cable that comes out of the negative cable and goes to a bolt above the inside of the headlight. Also I think ill just replace the battery cables aswell.

And where should I put the other end of the negative battery cable? It was connected to the top of the alternator shield(if that is the correct name)..

Re: First square. 1980 GMC
 

As far as I know, connecting to the alternator bracket is correct. That's the way it is on my '84. Although I've also seen it bolted to the exhaust manifold.

The negative is ground, so all you need is to hook it up something made of metal on the engine. Typically, alternator bracket or manifold is the best.

Re: First square. 1980 GMC
 

Hmm, I guess first thing to do would be to replace my ground that comes right off the negative cable to the back of the grille area. It's completely toast haha rubber melted almost completely off in a big section.

Then I guess I need to make sure the battery is fine as suggested above. It's only a week old with some cranks tried on it. Then go to the starter. Do I need to check out the alternator aswell?