The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 1988 Canadian GMC C1500 305 TBI w/TH400HD going into 1973 C20 Custom Crew Cab

dwmitchell61 · 08-27-2015, 07:10 PM

I started plumbing the fuel lines and returns today.

Someone had a loop in the auxiliary tank vent line where I could conveniently tap into it for the return line. You can see the 5/16" return from the fuel selector valve tapped into the 3/8" vent "loop" on the left. I also added a "pre-pump" filter in the fuel line to the selector valve:

The main tank on the right side was not so easy. It had a 1/2" vent line. Here you can see where I tee'd the 5/16" return line into the 1/2" line. I made a loop using 1/2" tubing as the tee would not fit between the tank nipple and the steel vent tube. so you can see the loop in this photo:

Here is the fuel selector valve. I still need to bolt it into place. Looks rather busy:

Here you can see the pre-pump filter from the right (main) tank:

I am still awaiting the PROPER fuel pump, one that runs 12-17psi instead of the 90-100psi...

08-27-2015, 07:10 PM	#15
dwmitchell61 Registered User Join Date: Jul 2015 Location: Benton City, WA Posts: 37	Re: 1988 Canadian GMC C1500 305 TBI w/TH400HD going into 1973 C20 Custom Crew Cab I started plumbing the fuel lines and returns today. Someone had a loop in the auxiliary tank vent line where I could conveniently tap into it for the return line. You can see the 5/16" return from the fuel selector valve tapped into the 3/8" vent "loop" on the left. I also added a "pre-pump" filter in the fuel line to the selector valve: The main tank on the right side was not so easy. It had a 1/2" vent line. Here you can see where I tee'd the 5/16" return line into the 1/2" line. I made a loop using 1/2" tubing as the tee would not fit between the tank nipple and the steel vent tube. so you can see the loop in this photo: Here is the fuel selector valve. I still need to bolt it into place. Looks rather busy: Here you can see the pre-pump filter from the right (main) tank: I am still awaiting the PROPER fuel pump, one that runs 12-17psi instead of the 90-100psi...