Onto my next issue

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.

77 k 20

Junior Member
Joined
Nov 21, 2023
Posts
14
Reaction score
7
Location
89445
First Name
ken
Truck Year
77
Truck Model
K20 Bonanza
Engine Size
350
I have a 77 K20 350 eng that has dual tanks and HAD a 6 port single wire transfer valve that took a dump and was replaced with a 3 port single wire. Figured what were supply lines that went to valve and then return line and vents which were hooked together by what they did. The engine has a Carter 3 line fuel pump. Now to the issue when driving with both tanks full fuel will go from the right, main, tank that I'm running on to the left, aux, causing it to overfill. I know how the valve works running off main compared to aux. Question: So if I run my aux tank first will that solve my issue or cause the main tank to overfill?
I did this same set up in my 72 K10 using a Blazer tank and the factory cab tank with a 2 line engine mounted fuel pump. On those tanks the sending units had 2 connections supply and return as the 77 has 3 supply return and vent.
Here's my thoughts now. Leave the 3 valve in place, take the return and vent lines and separate them so that they vent to atmosphere and replace the engine mounted 3 line fuel pump with a 2 line version. It worked well on the 72 for over 40 years.
Thoughts?
 

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
29,552
Reaction score
25,548
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
I'd leave the 3-port valve, install a returnless/ventless fuel pump, plug the return hoses to the tanks and let the vent lines do the venting.
 

77 k 20

Junior Member
Joined
Nov 21, 2023
Posts
14
Reaction score
7
Location
89445
First Name
ken
Truck Year
77
Truck Model
K20 Bonanza
Engine Size
350
Andy I agree with you Thank you for your thoughts.
 

Latest posts

Forum statistics

Threads
42,974
Posts
925,830
Members
34,537
Latest member
Wyatt78
Top