1980 F150 Shortbox 4x4

[gtanns]

Sorry I am a little late to this.

On the duel tanks there are 2 main truck wiring harness.

One is made for duel tanks & the other is not.

You will not find the plug to plug into the tank switch on that panel in your truck.

Also know the rear harness that plugs into the main harness under the master/booster is also different as it should have the 2nd tank sender plug and the tank switch valve (that bolts to the frame) wires.

Can you do with out them 2 harnesses? I am sure you can you will just have to make a harness to run along side what you have in the truck now now is all.

I know all this as I converted my 81 flare side to duel tanks but I had a 81 parts truck I took it all from so it was plug-n-play. Don't know if mine works yet as I am still re-building my truck.

Dave ----

Thanks Dave!

Yes there is a female plug on the back of my donor panel near the tank switch that is not there on the panel I have in there now (with no tank switch).

Re 'can you do without them 2 harnesses?' -- as you're saying do you think I could wire up my own 2nd harness to imitate the factory setup for two tanks and plug into the donor panel ive got? I have all the original wiring diagrams for the truck (with one tank) and I think I could figure it out with the right amount of hours but should probably get the diagrams for a dual tank setup to compare... Or better yet maybe get the whole wiring harness from a dual tank setup.

[gtanns]

Thanks Dave!

Yes there is a female plug on the back of my donor panel near the tank switch that is not there on the panel I have in there now (with no tank switch).

Re 'can you do without them 2 harnesses?' -- as you're saying do you think I could wire up my own 2nd harness to imitate the factory setup for two tanks and plug into the donor panel ive got? I have all the original wiring diagrams for the truck (with one tank) and I think I could figure it out with the right amount of hours but should probably get the diagrams for a dual tank setup to compare... Or better yet maybe get the whole wiring harness from a dual tank setup.

Engine update!

Well I've drained the piggy bank and after saving since 2012 getting a new engine built for this thing...starting in the next week ohh baby I'm excited.

I have a 351M which is a Cleveland block basically. Going to wash and clean the block.. use same heads but get a new crank to stroke it out to 4.0 inches and 400 CID ... new pistons comp cam valve train .. use a camshaft setup that will give more low end torque.. it's not too often that this would ever be over 5000 rpm.

Also I'm putting in one of these fitech EFI converters in lieu of a holley 650 carb.. they sound so awesome! Reliability, fuel economy...and essentially plug and play onto the engine. For en extra 500 bucks you'll earn that back in fuel savings after a year.

I'm using Canadian crate engines out of Vancouver, a guy named Rob Borden. Super great dude.

Attached is a pic of the dyno from a similar engine he just built.

Will probably put some tri-y headers and 2.5" exhaust. Turnaround time is not that long so expect to see some updates here in the next month or so! :)

[FuzzFace2]

Thanks Dave!

Yes there is a female plug on the back of my donor panel near the tank switch that is not there on the panel I have in there now (with no tank switch).

Re 'can you do without them 2 harnesses?' -- as you're saying do you think I could wire up my own 2nd harness to imitate the factory setup for two tanks and plug into the donor panel ive got? I have all the original wiring diagrams for the truck (with one tank) and I think I could figure it out with the right amount of hours but should probably get the diagrams for a dual tank setup to compare... Or better yet maybe get the whole wiring harness from a dual tank setup.

Look over your diagram for the single tank truck as I want to say it will also show the duel tank and if so you could follow it to make your own harness.

Now we all know the easy way is to get a duel tank trucks harness, both the main in truck one and the one that runs down the frame rail.

The easy one to make is the frame rail one and the easier one to get. Unplug under master/booster and follow it back along the frame rail.

The main one that is inside the truck runs across the top of the dash and goes out the fire wall on each side.

The right side does the heater/AC, charging system and power/solenoid.

The left side does the head & parking/turn lights up front, horn, wiper & washer and everything going to the rear for lights and the fuel tank senders & valve switch.

There other things I just hit the big ones.

I think someone removed the main harness without removing the dash so guessing it can be done.

When I did mine I was also using the dash from the parts truck as it had the AC vents (added factory AC to a non AC truck, not easy task) so I took the dash & wiring as 1 big bundle.

It was when I started checking dash plug wiring for heater/AC/fuel tanks (some were cut off the parts truck harness) between the parts truck harness and my truck I found the difference in the harnesses.

Now my 2 truck just happened to be the same years (1981's).

I know 1980 dash gauges had some different wiring than later years. You will most likely find a different year than 80 so if you get the gauge cluster you would not have to deal with the 80 only gauge deal.

I also think the mid to late 80's also changed wiring for the duel tanks so would need to watch for that.

Or maybe it is for electric fuel pumps and non fuel pumps?

Just wanted to give you a heads up on what you need to look out for.

Dave ----

[Gary Lewis]

Engine update!

Well I've drained the piggy bank and after saving since 2012 getting a new engine built for this thing...starting in the next week ohh baby I'm excited.

I have a 351M which is a Cleveland block basically. Going to wash and clean the block.. use same heads but get a new crank to stroke it out to 4.0 inches and 400 CID ... new pistons comp cam valve train .. use a camshaft setup that will give more low end torque.. it's not too often that this would ever be over 5000 rpm.

Also I'm putting in one of these fitech EFI converters in lieu of a holley 650 carb.. they sound so awesome! Reliability, fuel economy...and essentially plug and play onto the engine. For en extra 500 bucks you'll earn that back in fuel savings after a year.

I'm using Canadian crate engines out of Vancouver, a guy named Rob Borden. Super great dude.

Attached is a pic of the dyno from a similar engine he just built.

Will probably put some tri-y headers and 2.5" exhaust. Turnaround time is not that long so expect to see some updates here in the next month or so! :)

Screenshot_20181117-114911.png

Those numbers look good.

Do you know what pistons he's using. My understanding is that the only pistons that will get more than 8:1 compression come from Tim Meyer. But to get those power numbers surely he's got more than 8:1 compression in the engine.

Anyway, congrat's! That's gonna put some spunk in the truck, for sure.

[gtanns]

Thanks Dave!

Yes there is a female plug on the back of my donor panel near the tank switch that is not there on the panel I have in there now (with no tank switch).

Re 'can you do without them 2 harnesses?' -- as you're saying do you think I could wire up my own 2nd harness to imitate the factory setup for two tanks and plug into the donor panel ive got? I have all the original wiring diagrams for the truck (with one tank) and I think I could figure it out with the right amount of hours but should probably get the diagrams for a dual tank setup to compare... Or better yet maybe get the whole wiring harness from a dual tank setup.

Look over your diagram for the single tank truck as I want to say it will also show the duel tank and if so you could follow it to make your own harness.

Now we all know the easy way is to get a duel tank trucks harness, both the main in truck one and the one that runs down the frame rail.

The easy one to make is the frame rail one and the easier one to get. Unplug under master/booster and follow it back along the frame rail.

The main one that is inside the truck runs across the top of the dash and goes out the fire wall on each side.

The right side does the heater/AC, charging system and power/solenoid.

The left side does the head & parking/turn lights up front, horn, wiper & washer and everything going to the rear for lights and the fuel tank senders & valve switch.

There other things I just hit the big ones.

I think someone removed the main harness without removing the dash so guessing it can be done.

When I did mine I was also using the dash from the parts truck as it had the AC vents (added factory AC to a non AC truck, not easy task) so I took the dash & wiring as 1 big bundle.

It was when I started checking dash plug wiring for heater/AC/fuel tanks (some were cut off the parts truck harness) between the parts truck harness and my truck I found the difference in the harnesses.

Now my 2 truck just happened to be the same years (1981's).

I know 1980 dash gauges had some different wiring than later years. You will most likely find a different year than 80 so if you get the gauge cluster you would not have to deal with the 80 only gauge deal.

I also think the mid to late 80's also changed wiring for the duel tanks so would need to watch for that.

Or maybe it is for electric fuel pumps and non fuel pumps?

Just wanted to give you a heads up on what you need to look out for.

Dave ----

Yes! I found in the wiring diagram (1980 F100-350) page 3 shows the the fuel gauge/sender and yes, and includes the 2nd aft tank with it.

Also, if anyone wants me to upload the entire 10 page wiring diagram, i'll do that in another thread or something let me know.

I got to thinking though.. I'm wondering if it'll be better in the long run to 'keep it simple' and avoid the wiring etc and instead get a custom tank cut that is dual capacity but actually only one tank. Would like to hear some thoughts on this new idea:

*See pic above of current driver side mid tank and muffler

IDEA:

- Fabricate a custom tank

- It would essentially be like running a second side side tank on the passenger side of the driveshaft (where the muffler is currently)

- at the very front bottom of the tank, (leaving enough access to the u-joint) have the driver and passenger side tanks fabricated together so the bottom of the tank would be like a big horseshoe, so that they're connected

- The issue is the muffler. I'm getting a custom exhaust (single side dump on driver and passenger side), and if you look at the pic of the midtank and muffler further up the thread, you'll see i'd have to squeeze a round muffler beside the transfer case or something.

I'm thinking that this would save the electrical work, and then I could also use the aft tank space for a spare tire... ?

Here is a pic from the passenger side where you can see I'm thinking the tanks could connect under the u-joint. (the muffler has been removed)

What'r your guys thoughts?

And a pic from the back:

 

[gtanns]

Those numbers look good.

Do you know what pistons he's using. My understanding is that the only pistons that will get more than 8:1 compression come from Tim Meyer. But to get those power numbers surely he's got more than 8:1 compression in the engine.

Anyway, congrat's! That's gonna put some spunk in the truck, for sure.

Yes, I'm pretty fired up to get this thing fired up!

I was wondering the same thing RE compression: He's getting 9.2 by shaving the face of the block down, and also shaving the face of the heads down. The pistons will still still stroke ok, and there is less space to do so, so it increases the pressure

I'm Canadian but take US holiday's so had yesterday off to pull my engine with a buddy in my underground parking garage We got it out by about 3 pm so just before everyone was gettin home Rented the hoist and everything and started filling the mop buckets with fluids. Got er out and left it @ the shop today!

Here are a few pics:

Lots of space in the bay to take out with the header's on and no jacks. I sawzalled the old exhaust as it was rusted shut to oblivion. Man we tried to get my buddies 440 out of his 73 Challenger the night before.. lol man there is no room to move in that thing. We got hung up and had to call it another day in the rain, thankfully we had my underground garage for mine :)

Bellhousing on 351M: the two holes second closest to the top are dowels, so didn't have to screw those out. We got held up pulling it out and wondered why, but amateur error didn't undo the bolts at the bottom of the bellhousing (the easiest ones) that hold the gasket on there. So we were scratching our head there for a sec then realized the gasket was holding it up.

Engine Bay:

Success:

[Rembrant]

I got to thinking though.. I'm wondering if it'll be better in the long run to 'keep it simple' and avoid the wiring etc and instead get a custom tank cut that is dual capacity but actually only one tank. Would like to hear some thoughts on this new idea:

What'r your guys thoughts?

Since I only have the one small swb fuel tank, I know little the dual tank set-up...but it would seem to me the dual tank set-up would be the lesser of two evils, no? Isn't the rear tank huge (or there is a huge option)? What is troublesome about it?>..The plumbing and wiring, or?....

The downside is you lose the space for the underside spare.

I guess it depends on your angle. If you have the time and ability to fab a custom dual tank in one (sort of), then maybe that is preferable over the factory dual tank set-up. I would find the plug and play part of the dual tank an easier install personally, but like I mentioned above, I've not studied the system, so I know little about it.

I'm running with no spare underneath, and I'm OK with that locally. If I were to go on a trip, I'd throw the spare in the bed. I'd like to have more fuel capacity, but my current range (I believe around 400 km, or 250 miles) is about as far as I want to drive without a break anyway...in the truck at least.

In any case, if you do build a custom tank, it will be interesting to see how it works out.

 

[Gary Lewis]

I got to thinking though.. I'm wondering if it'll be better in the long run to 'keep it simple' and avoid the wiring etc and instead get a custom tank cut that is dual capacity but actually only one tank. Would like to hear some thoughts on this new idea:

What'r your guys thoughts?

Since I only have the one small swb fuel tank, I know little the dual tank set-up...but it would seem to me the dual tank set-up would be the lesser of two evils, no? Isn't the rear tank huge (or there is a huge option)? What is troublesome about it?>..The plumbing and wiring, or?....

The downside is you lose the space for the underside spare.

I guess it depends on your angle. If you have the time and ability to fab a custom dual tank in one (sort of), then maybe that is preferable over the factory dual tank set-up. I would find the plug and play part of the dual tank an easier install personally, but like I mentioned above, I've not studied the system, so I know little about it.

I'm running with no spare underneath, and I'm OK with that locally. If I were to go on a trip, I'd throw the spare in the bed. I'd like to have more fuel capacity, but my current range (I believe around 400 km, or 250 miles) is about as far as I want to drive without a break anyway...in the truck at least.

In any case, if you do build a custom tank, it will be interesting to see how it works out.

First, on the wiring diagrams - I have the 1985 and '86 diagrams on the website (Electrical/Wiring Diagrams) and would be happy to add your 1980 diagrams to that. But, and this is a big "but", I've learned that they have to be in pdf and at least 600 dpi. They really aren't legible when you get them on a computer screen, so you have to be able to zoom way into them to make them useful. But, if you can do that I'd love to have them.

As for the fuel tank, the concern I have with a tank on both sides is the problem it creates with where you run your exhaust. But, if you can get around that then perhaps it is a viable option.

Another single-tank option is either a 33 gallon Bronco tank or the 38 gallon upgrade to the Bronco tank. In either case you won't get a spare tire under the rear, but it would be a much simpler fuel system.

[FuzzFace2]

First, on the wiring diagrams - I have the 1985 and '86 diagrams on the website (Electrical/Wiring Diagrams) and would be happy to add your 1980 diagrams to that. But, and this is a big "but", I've learned that they have to be in pdf and at least 600 dpi. They really aren't legible when you get them on a computer screen, so you have to be able to zoom way into them to make them useful. But, if you can do that I'd love to have them.

As for the fuel tank, the concern I have with a tank on both sides is the problem it creates with where you run your exhaust. But, if you can get around that then perhaps it is a viable option.

Another single-tank option is either a 33 gallon Bronco tank or the 38 gallon upgrade to the Bronco tank. In either case you won't get a spare tire under the rear, but it would be a much simpler fuel system.

Ok on the tanks factory you had side tanks 16gal on the SB trucks, 19gal on the LB trucks.

Out back you had a 19gal tank and you had the spare tire under it.

Now others have said what they find why not to have a side tank on the right side but one that has been missed is how to fill it.

In the early days Chevy had them on both sides and part of the problem was how to get fuel in it?

Hose most of the time is too short to reach and forget it if you have a cap on the bed.

Could fill 1 tank the turn truck around but if you don't shut the pump off someone can sneak in and fill on your dime. If you do shut if off then start again using the same credit card the card may not work as they think it was stolen.

SO to KISS use factory tanks and if you need more fuel run an after market 33gal or 38gal rear tank but you can not have the spare tire mounted under it.

Dave ----

[gtanns]

Ok on the tanks factory you had side tanks 16gal on the SB trucks, 19gal on the LB trucks.

Out back you had a 19gal tank and you had the spare tire under it.

Now others have said what they find why not to have a side tank on the right side but one that has been missed is how to fill it.

In the early days Chevy had them on both sides and part of the problem was how to get fuel in it?

Hose most of the time is too short to reach and forget it if you have a cap on the bed.

Could fill 1 tank the turn truck around but if you don't shut the pump off someone can sneak in and fill on your dime. If you do shut if off then start again using the same credit card the card may not work as they think it was stolen.

SO to KISS use factory tanks and if you need more fuel run an after market 33gal or 38gal rear tank but you can not have the spare tire mounted under it.

Dave ----

Yes, the issues with both the space for the muffler and the filling of both tanks from one filler neck have been the biggest obstacles here. I believe there is a way to cover both those obstacles with the design i've got. I sent this off to a fabrication shop today, so we'll see what they think and of course what your guys thoughts are on it too.

Below is my truck and where the exhaust exits (passenger side only) - I’d like this same exhaust positioning, but one on both passenger and driver side:

This is the view from underneath, showing the gas tank on the driver side, and the muffler and exhaust on passenger side:

In the photo above, the space to the right of the transfer case is where I want to make space for the muffler. Below is a close of up of that space beside the transfer case. Note the bent grey metal piece on the left is just a protective sheet, can be re-fabbed or moved to make space.

2nd photo of same space as above:

See the gas tank design below along with the dimensions of the space for the muffler. The LxWxH dimensions for each side of the driveshaft are the same dimensions as the original stock side tank. I believe the new fabricated tank could add an inch in height to the original. Tried to do it to scale.

This shows the space to the back of the tank and where the tank would need to safely accomodate a 7 1/2 " travel on the driveshaft from the rear leafs.