How are the factory dual saddle fuel tanks supposed to be routed?

[Casca2525]

My dash doesn't have a cutout for that switch on it. Instead, my dash has this switch:

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That switch is mounted right under the steering column on the left side.

Can that switch be used instead of the one lined to above? You know, just to keep a factory appearance and avoid cutting a hole?

if your worried about looking "factory" stay with the classic kit it looks sturdier than the amazon and the bat handle toggle switch it comes with matches yours in appearance and is the exact same size hole and will slide right in and as long as its mounted right the label will line up! if not rotate the switch body 180 degrees

 

[Casca2525]

Wow I just looked at the price of those holley pumps. I'd buy an external FPR a 6 port Pollak valve and 2 ep 381 pumps on 87 senders,I can buy all that for the price of 1 Holley pump and probably have change .

ok, so as I read this: I need to get a non in tank pump sending unit cut the pick up line and fit in the ep381 pump unit there by creating and in tank pump sending unit?

 

[Ricko1966]

ok, so as I read this: I need to get a non in tank pump sending unit cut the pick up line and fit in the ep381 pump unit there by creating and in tank pump sending unit?

No you use 87 senders which use tbi pumps but instead of using tbi pumps you use ep381 pumps

 

[Ricko1966]

thanks for this, I am in a similar boat, quick question did any of these trucks come with 3 tanks? my Scottsdale w 454 has 2 filler doors on drivers side 1 in front of the flare saddle and currently only tank and one at the back of the flare, like a logical spot for a rear tank, as well as a 3rd on the right where the right side saddle tank would be?

I ask because I travel regularly from eastern Ontario to south western Ontario, pulling a 26ft house trailer, about a 1600km round trip, so I'm thinking 3 tanks could be handy

No, three tanks was never an option. Also you should ask your own questions on your own threads,it gets confusing when we are working with multiple vehicles and situations on the same thread.

 

[Old Guy Bill]

I went through the complete dual tank system when rebuilding my truck.
New tanks, new lines, the original six port valve, it was tested with air and worked fine. This includes the return line, which is 1/4", the vent line is the 5/16" one.
The only change I made was switching the tank & return lines at the valve, this made the main tank the left side. It also requires flipping the dash switch in the bezel.

 

[Casca2525]

Also you should ask your own questions on your own threads,it gets confusing when we are working with multiple vehicles and situations on the same thread

oh ok sorry

 

[Ricko1966]

oh ok sorry

NBD it just gets things confused when we start working on 2 or 3 different vehicles. Questions meant for car 2 are assumed to be for car 1 etc.

 

[AuroraGirl]

I have a 75 Custom Deluxe K20 with factory dual tanks. I had wiring "issues" as well. IMO, the best way to fix all that was to replace the FACTORY pickups in the NEW tanks, buy the correct transfer pump that mounts in the frame rail......and from there it goes to the mechanical fuel pump. I also replaced the original in cab fuel switch (FACTORY) and kept the old one as a spare just in case. The only thing I changed was the fuel pump to a Holley blue with a pressure regulator and DON'T FORGET FUEL FILTERS ! This is probably the easiest way to get back to 'normal'. You can use the mechanical fuel pump if you want to..........but lately the quality of aftermarket mechanical fuel pumps has been very sketchy. I went through THREE pumps before I said to hell with it and went to an electric fuel pump and a pressure regulator. I installed a much higher horsepower engine and didn't want any fuel starvation. These old square bodies like to drink. So , in short I would say.......TRY to remain as much factory as you can. They worked well when new and occasionally you might have to replace a rotten fuel line. But I'm running stainless 3/8" fuel line and don't have much exposed rubber anywhere. Tuck everything up nicely. Wire it NEATLY. Protect the wires! It can be frustrating at times. Finding a GOOD ground is essential. 90% of these fuel problems are ground related. Take your time and use all the drawings the other fellas have posted and you'll be ok. Good luck.

TRANSFER PUMP? What TRANSFER PUMP? do you mean valve?

 

[75BEASTK20]

Yeah, my bad. It's not a pump. More of a valve switch to use whichever tank you pick.

 

[LeperGnome87]

I would go with an in tank electrical pump from an 87 chevy. Grey wire runs your pump. Purple wire runs your float. Then get a switch from an 87 chevy and wire it into a relay and that way you can get rid of the stupid selector valve. Those never worked right anyway. The switch was a simple on and off switch. You may need to grind a tab off of one terminal. Check out Ugly Truck on YouTube, he has a lot of videos on fuel systems. Mainly for LS swaps but im sure you can adapt it to what you are doing

 

[Ricko1966]

I would go with an in tank electrical pump from an 87 chevy. Grey wire runs your pump. Purple wire runs your float. Then get a switch from an 87 chevy and wire it into a relay and that way you can get rid of the stupid selector valve. Those never worked right anyway. The switch was a simple on and off switch. You may need to grind a tab off of one terminal. Check out Ugly Truck on YouTube, he has a lot of videos on fuel systems. Mainly for LS swaps but im sure you can adapt it to what you are doing

I do not believe this. If you have a return system,and you should, you won't have any way to pick which tank fuel returns too,so you can end up over filling one tank. Aren't you having problems blowing the needle off the seat with this arrangement? Are you running a return line from the regulator? Is it big enough,otherwise it becomes a restriction and fuel pressure keeps building because it can't escape through the restrictive size of the return line. Result,you blow the needle off the seat and carb pukes fuel out the bowl vent.

 

[LeperGnome87]

Nope, i got a 5/16 return line to an adjustable fuel regulator and 3/8 for the feed line. I'm still testing stuff but I will post pictures soon. But at the same time i could be wrong, my in tank pump i switched to is a 15 psi pump i think, i need to double check my previous posts.

 

[Broken85]

Nope, i got a 5/16 return line to an adjustable fuel regulator and 3/8 for the feed line. I'm still testing stuff but I will post pictures soon. But at the same time i could be wrong, my in tank pump i switched to is a 15 psi pump i think, i need to double check my previous posts.

I think what Ricko is also asking is how are you selecting which tank the return line is going to without a switch valve??

 

[Grit dog]

Nope, i got a 5/16 return line to an adjustable fuel regulator and 3/8 for the feed line. I'm still testing stuff but I will post pictures soon. But at the same time i could be wrong, my in tank pump i switched to is a 15 psi pump i think, i need to double check my previous posts.

Why would you have a regulator on return line?

 

[Radiohead]

Why would you have a regulator on return line?

Right? The I.D. of the hose does a pretty good job of it as it is.