Fuel tank selector for 78

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

RoryH19

Full Access Member
Joined
Aug 21, 2015
Posts
1,668
Reaction score
1,081
Location
Texas
First Name
Rory
Truck Year
1987
Truck Model
R10 Silverado SWB
Engine Size
350 TBI
apparently its not sold anymore, I didnt realize the 3 port 1 wire was easier to find than the 6 port.


If you want to retrofit, there is a kit I just linked from SMP to use the later motorized valve with 6 ports, mounts in place and pipes the same. will last longer but requires more than swap.

Honestly, Im lazy enough to just use two 3 ports... lol. maybe ensure the power supply is better like relayed wi9th good gauge wire so the solenoid engages positvley every time and also if possible a filter in line before the valve for the send pipes would probably increase their life span.

Just an idea
Right, I've seen the 3 port or the newer 6 port style. I'll probably just go with the newer style and rewire where needed. I think I have to change the dash switch and the plug.
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,206
Reaction score
6,186
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
Right, I've seen the 3 port or the newer 6 port style. I'll probably just go with the newer style and rewire where needed. I think I have to change the dash switch and the plug.
oh common you dont like the idea of improving on the oe 3 port by having twice as many failure points.. oh wait.. Lol.
That kit has a switch and the connector. if you want the right switch you only need to slightly file the opening and buy a new switch.
the kit probably doesnt even replace the OE, it probably uses the switch on the truck to switch the sender(I think) and the toggle to switch the tanks. i think. no idea.
You must be registered for see images attach

hmm
 

RoryH19

Full Access Member
Joined
Aug 21, 2015
Posts
1,668
Reaction score
1,081
Location
Texas
First Name
Rory
Truck Year
1987
Truck Model
R10 Silverado SWB
Engine Size
350 TBI
oh common you dont like the idea of improving on the oe 3 port by having twice as many failure points.. oh wait.. Lol.
That kit has a switch and the connector. if you want the right switch you only need to slightly file the opening and buy a new switch.
the kit probably doesnt even replace the OE, it probably uses the switch on the truck to switch the sender(I think) and the toggle to switch the tanks. i think. no idea.
You must be registered for see images attach

hmm
Yeah, I'll pass on the 3 port :)
The 6 port wiring looks pretty straight forward. Just need to use an 81-86 switch I think.
 

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
29,087
Reaction score
23,894
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
Wait... the single-wire 6-port is the one that's hard to find? I thought it was the 3-port that was hard to find?
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,206
Reaction score
6,186
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
Wait... the single-wire 6-port is the one that's hard to find? I thought it was the 3-port that was hard to find?
It used to be, then it switched

ill see myself out

I know for a fact like early this year I recall being able to find plenty of those but no 3 ports. I almost bet you the Ac delco part does runs, sells out, stays that way for a while, then they run some and that was the end of those supplies

The rear window defroster/FM antenna module on the park avenue is a literal guarantee to be needing replacement after 50+k miles no matter what damn near, and i had people trying to pay me for mine when I only got it a month or two before them.

Then recently it came out of being "discontinued" and they are happy again

I also have a couple motorcraft parts for a 300 I may be wise to not put on mine and try and hustle.. lol
 

RoryH19

Full Access Member
Joined
Aug 21, 2015
Posts
1,668
Reaction score
1,081
Location
Texas
First Name
Rory
Truck Year
1987
Truck Model
R10 Silverado SWB
Engine Size
350 TBI
It used to be, then it switched

ill see myself out

I know for a fact like early this year I recall being able to find plenty of those but no 3 ports. I almost bet you the Ac delco part does runs, sells out, stays that way for a while, then they run some and that was the end of those supplies

The rear window defroster/FM antenna module on the park avenue is a literal guarantee to be needing replacement after 50+k miles no matter what damn near, and i had people trying to pay me for mine when I only got it a month or two before them.

Then recently it came out of being "discontinued" and they are happy again

I also have a couple motorcraft parts for a 300 I may be wise to not put on mine and try and hustle.. lol
Yep.
I can find the 3 port, 1 valves on Amazon now or the newer multi wire 6 ports.
1 wire 6 ports must be out or discontinued.
 

Powerhouse Ranch

3G Connoisseur
Joined
Jan 6, 2021
Posts
1,459
Reaction score
2,560
Location
PA
First Name
Luke
Truck Year
1980 & 1988
Truck Model
C25 & V15
Engine Size
454 & 350
Does anybody have a spare 6 port 1 wire selector valve laying around? Only thing keeping me from getting the '74 beast from up and running. Would kill for one. . .
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,206
Reaction score
6,186
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
Does anybody have a spare 6 port 1 wire selector valve laying around? Only thing keeping me from getting the '74 beast from up and running. Would kill for one. . .
You can wire 2 3 ports or you wait for the aftermarket to pump out the next batch (who knows ) or you can do the upgrade to the 6 port oogles of wires which needs new switch n stuff
 

Juggernaut

Full Access Member
Joined
Apr 11, 2021
Posts
204
Reaction score
220
Location
Illinois
First Name
Greg
Truck Year
78
Truck Model
K20
Engine Size
350
I ran into this problem a few years ago. I couldn't find the 6 port 1 wire. I found several 3 port 1 wire, but when I ordered them, they would come in with 5/16 fuel line fittings, even when advertised with 3/8. I finally went with the 6 port motorized switch and connector from Rock Auto. And the motorized switch has 5/16 return lines instead of the 1/4 used on the sending units, but I just had to make it work. The wiring is a little different, you have to run a third wire to the motorized switch, and you have to change the switch in the dash to a mid 80's switch
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,206
Reaction score
6,186
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
I ran into this problem a few years ago. I couldn't find the 6 port 1 wire. I found several 3 port 1 wire, but when I ordered them, they would come in with 5/16 fuel line fittings, even when advertised with 3/8. I finally went with the 6 port motorized switch and connector from Rock Auto. And the motorized switch has 5/16 return lines instead of the 1/4 used on the sending units, but I just had to make it work. The wiring is a little different, you have to run a third wire to the motorized switch, and you have to change the switch in the dash to a mid 80's switch
if one was insistent on keeping the dash switch and wanted a solenoid and not a motorized valve, 2 3 ports and a 1980 delay relay would make a decently reliable system, but its a lot of fab/figuring out compared to just doing the newer setup or etc
 

Forum statistics

Threads
42,070
Posts
908,400
Members
33,545
Latest member
GrayWK
Top