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The Wife's Dually - '82 K30 dually

I pulled the valve covers on the motor I pulled out of the grey dually and found these. These are the desirable ones, correct? Looks like March 9th of 1978 was the production date. I guess if for some reason I'm not satisfied with the built up motor from the black dually I could go to the trouble of putting these on...

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Does anyone happen to have a plumbing diagram for the fuel system/dual tanks on these trucks? The PO had cut the dual tank manifold out of the equation and was only running one tank (driver's side if I recall correctly), so I need to know how to plumb it back the way it came from the factory.
 
Pretty common with these trucks. Just picked up a k30 myself this week and it has the same thing going on.
I don't know where you can get a diagram. But I see lmc has the selector valve and lines listed in their catalog page 49 and 53.
I am going to check inline tube as well.
Hope @sweetk30 will have a pic or diagram.
 
Does anyone happen to have a plumbing diagram for the fuel system/dual tanks on these trucks? The PO had cut the dual tank manifold out of the equation and was only running one tank (driver's side if I recall correctly), so I need to know how to plumb it back the way it came from the factory.


its actually not too difficult...
i have dual tanks and was going to just throw a 40g burb tank in but im not going that route.

fyi this is for a 1978 where it still used a 1 wire selector valve vs the 5 wire...

so you have 2 fuel lines going from mechanical fuel pump (1 for fuel and 1 for return ??? I think)
so 2 lines run back into selector valve.
out of the valve is 2 hoses per tank...
1 for fuel and 1 for vent/return (dont know which)

on each tank is 3 lines...
1 for fuel to selector valve
1 for fuel return or vent to valve
1 for vent that is like 2-3"

found this... Great info http://67-72chevytrucks.com/vboard/showthread.php?t=558564

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as seen here there are 3 different types of floats...

1, 2 and 3...

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Great info. Thanks!

I ended up getting my selector valve and harness from Rock Auto I think. Valve was like half the price of LMC IRC. I did get new crossover lines for between the tanks from LMC though.
 
Great info. Thanks!

I ended up getting my selector valve and harness from Rock Auto I think. Valve was like half the price of LMC IRC. I did get new crossover lines for between the tanks from LMC though.

after winter im doing 2 new tanks with all new hardline !!!!!!!

so which valve do you have? 1 wire or 5 wire? 4in/2 out or 2in/1 out?
 
I have no pics . . . . sorry guys .

but I do have a 3 hose each splitter valve from a parted 2 tank diesel . even have switch and wiring . . . . only thing is I don't know condition as 1 tank wasn't plumbed in from fact it sat for years and fuel was nasty and to get it to run last owner bypassed and just ran 1 tank and flushed it first .
 
Fuel tank brackets and straps put back on today, and tanks mounted. One strap was short a bit, so the bolt section was cut and a small section welded in to make it longer. Crossover fuel lines installed (purchased from LMC), but I'm confused as to what the three small sections for each one is for. One line is the fuel line from DS tank to manifold, one is return line from DS tank, and one is vapor line. The fuel and return I get, but not sure what to do with the vapor line and the three small sections. I'm guessing the small sections somehow attach to the frame and are the hard lines that go between the manifold and the PS tank, but the PO had by-passed the manifold and was only running off one tank. Anyone have some pics that might show where/how these small sections are mounted/plumed?

Also, the main lines (Fuel from fuel pump, and return line) don't line up with the manifold. They are way to close (in fact go too far past) the manifold to plumb them with flexible hose. See the last pic. Anyone have suggestions? I looked at loosening the brackets holding the hard lines on the frame that are between the manifold and the engine, but it doesn't really look like I can get any space by doing that. Again, pics or suggestions are welcome. Thanks!

@RootBreaker @sweetk30 ?

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so this is where I am lost as well.... so I will just throw notes out as I do not know a lot but know very little... maybe it helps (after typing i see it wont help sorry bud..)...
I didnt realize a few things on your setup until I rechecked it in your pics.
your setup is different than mine bigtime.

I only have 2 lines from each tank to the solenoid. fuel line and return line. I do have a 3rd on each tank but they are just a very small 2-3" rubber line with the 1 way vent on them.

so I am thinking instead of doing that, the newer setup brings all vents back as well but that doesnt make sense as your solenoid only has 2 lines for each side... weird...
 
I think the factory set up on mine must have been similar to yours, but these were originally diesel tanks. The small vent lines you have are, in my case, lines that run back to a valve on the frame that drains water. I no longer need that since this is now a gas set up. I'm assuming you are correct, that this new set up ties all the vent lines together, I'm just not sure how/where they end up and what goes on the end of them. Is there a one way breather valve I need to put on the end of my vent lines? The three small hard lines I pictured might not be needed in my case. Not really sure, but they came with the new lines (which fit all trucks from '81-'87), so maybe they are needed in some applications and not in others? I've got one random small line sitting on my frame on the PS, but it isn't plumbed to anything.

Our solenoids are probably the same. Mine has the following:

2 lines on the motor side (fuel and return)
4 lines on the back side (LH fuel and return, and RH fuel and return)

The vent lines must hang free like yours. I'll have to pull out my new sending units and see if I can figure anything additional out from those.
 
I wonder if maybe I don't need them. Not sure I really even need the crossover vent line, do I? Can't I just run some small rubber lines off the sending units and cap them with a one way breather of some sort?
 
I got the motor pulled out of the black dually yesterday. Need to go pick up an Easy Out to remove the bolt I broke off in one of the valve covers, and I'm going to blast and repaint the headers with something better than the cheap paint that comes on these Hedmans. I also got the bolt in steering box brace installed and the steering box back on.

I'm still in a bit of quandary about what to do with the vapor line for my dual tanks. I think I'll run by O'Reilly's and see if they have a one way valve or something I can plumb in to both tanks. I guess maybe the factory vapor line used to run up to the charcoal canister? Seems like most people ditch the charcoal canister, so I assume I don't need to do that here.

@ryoken are you running dual tanks on your CC? Do you have a vapor line plumbed?

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I'm down to one stocker.. no more diverter valve.. soon to be full-blown aftermarket setup... iirc, factory is a single line from the diverter valve up to the canister...
 
I can't find a hard line for the vapor line on this frame that would go up to the canister. Just a feed line and a return line go up to the front of the truck. I went ahead and just ran some short sections off the vapor port from the sending units that I will cap with a one valve of some sort. That appears to be the way it is set up on the black dually I have from what I can tell.

I got a few things done yesterday, but ran into an issue.

Completed:
  • ORD steering box brace installed. I probably installed it about six times since the front crossmember already had a small hole in it where the 1/2" bolt goes. I tried to enlarge it, but it was just off a little bit, so it took some grinding to get the hole open a bit more. Oh, and don't forget to install the single factory bolt that is used into the box BEFORE you install the brace. I wasn't paying attention and the only bolt that gets reused is the one that you can't access if the brace is installed. Yup, did that twice.
  • Sending units installed into fuel tanks, and plumbed (other than capping the vapor lines with one way valves). Still need to plumb the lines from/to the motor to the switching valve.
  • Broken valve cover bolt extracted from motor. This went fairly well, other than not following the Easy Out instructions exactly. I did drill the hole into the end of the bolt using the smallest bit, but then I went up a size when I flipped it around to use the extractor part. This actually allowed it to grab the bolt better and it came right out.

Issue:
  • The main issue is my motor mounts. I'm going to start a thread in the garage (found here: https://ck5.com/forums/threads/big-block-motor-mount-confusion.328748/ ) to get a bit more traffic to it, but the gist of it is that the motor mounts I pulled off the BBC from my 4x4 frame do match the motor mounts that came off the black 4x2 frame. The Prothane replacement mounts I got don't fit the ones from the 4x4 dually, but it looks like they will fit the ones from the 4x2 dually. Not sure if the 4x4 ones are different because this truck was originally a diesel, or what, but it had a 454 in it so I assumed they would fit. Not the case. In the pics below the freshly painted mount is from the 4x4 frame. Then there is a pic of the mount that is on the 4x4 frame, then a pic of the 4x2 frame, then a pic of the 4x2 mount placed on the 4x4 frame. The 4x2 mount (which is obviously the BBC mount) doesn't line up with any of the holes on the 4x4 frame. Need to figure out how make that work.

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