1976 k20 gas tank swap

[crusty_jalapeno]

Hi folks, so im about to start the project i mentioned in my introduction post. She is 1976 K20 with crate 400, 69k miles on odometor. 200 4r transmission. There are some questions(tried to read as much as possible, have a general idea how to do it).

I need help with the shopping list if you may. I want to take down 16 gal tanks and replace them with 20 gal tanks.
I am thinking of adding EFI comes summer time.so far as parts go i know i need

GAS tanks x 2
Sending units x 2 (for each side)
2 rings
4 new straps
Electric fuel pump?
What else am i missing?

I ll be gratefull for any advice. This saturday im taking old parts out, but would like to order before then. Thank you guys.

 

[Grit dog]

Consider separate pumps in each tank. Although 1 good pump set up right will doo the trick.
Filler and vent hoses
Anti squeak material.
New fuel hose, 3 sizes.
Possibly tank mounting hardware.

 

[oldretiredafguy]

Make sure you get the replacement tanks built for 1987 and up trucks. They have baffles, and are set-up to handle the high pressure fuel pumps required for TBI/EFI. Also, the fuel tank selector switch is different for 81-86 carb trucks and 87 up TBI vehicles.

 

[scrap--metal]

I want to take down 16 gal tanks and replace them with 20 gal tanks.

The rubber filler necks to connect the the tank to the side of the box are different length when using 16 vs 20 gallon tanks. You can probably shorten the rubber sections that you have, but I've just replaced them.

Also, make sure your rubber filler neck is the correct diameter for your new gas tanks. Early trucks used a smaller diameter neck on the fuel tank than the later squares.

 

[scrap--metal]

Make sure you get the replacement tanks built for 1987 and up trucks. They have baffles, and are set-up to handle the high pressure fuel pumps required for TBI/EFI.

IDK about the '87 tanks with internal baffling, but the '82-'86 tanks without baffling use a larger different diameter neck on the fuel tank than what would've originally been on his '76.

 

[crusty_jalapeno]

Hey thanks for all the replies. Just took first tank down about an hour ago. Turns out its in really good condition. I might just stay with 16 for while untill i get EFI bought. I had to cut one of the hoses because it had a penny wide crack in it right where the clamp was. So im assuming i have to get new hose, otherwise i m leaning towards Eastwood seal kit. I got time to wait a bit anyway.

 

[Juggernaut]

Don't buy the Eastwood kit until you remove the straps. You may find the metal pitted and nearly rusted under the anti-squeak pads. I've had to throw away several tanks rusted out in this area

 

[crusty_jalapeno]

Don't buy the Eastwood kit until you remove the straps. You may find the metal pitted and nearly rusted under the anti-squeak pads. I've had to throw away several tanks rusted out in this area

thanks for a heads up, yeah i ordered the straps aswell. Worst case scenario still to original plan and get new tanks. But from what i can tell it looks pretty solid so far

 

[mtbadbob]

What about a port-valve switch??

 

[crusty_jalapeno]

Hey folks, little update with some questions.
I was able to save and reinstall passanger side main gas tank, kept it 16 gal for now. Truck starts, its not street legal yet but it runs. Working on installing a 20 gal on driver side.
Got new lines new sending unit, but having problem of finding fuel neck gas and vent hoses in town.

Scrap metal mentioned that the hoses are diffrent lenght. Im looking at LMC magazine and tgey have a part but it dosent calarify if its for 16 of 20 gal. Looking for second opinion or where to get those. Old ones are in pretty bad shape and cutting adjusting them seems like a bad idea.