3 port fuel tank selector valve

[75gmck25]

The HEI was new for ‘75, but it was not unusual for GM to make running changes near the model year changeover, so maybe it made it into a few ‘74 trucks.

My ‘75 repair manual is actually just a small supplement to the ‘74 manual, with sections on cruise control, HEI, A/C ( I think they changed from using a TXV to an orifice tube), and a couple other items.

 

[eric 87]

I know this thread is old. But thought if anyone looked at it......
I am in the middle of a TBI to carb swap. Talking amongst yourselves can begin. But I decided I want to not only swap but completely get rid of my computer and all the extra wires. I am going to run this universal 3 port selector valve by Tanks Inc. Electric Holley pump that is 4-7 psi so no regulator. I will use the dash switch to operate both the sending units and to power this selector valve. I will run the pump through both the oil pressure switch and a relay.
I took off the protective plate from factory to find the prev. owner had bypassed the entire 6 way valve. He had only the drivers tank going to the engine. I never was able to use the pass side tank because the minute I hit the switch it killed the engine. Well looking at the port he had a loop of tubing going from one side of the valve back around to the other side. I am thinking the pass side tank had been left in a loop inside the valve. I used to hear the pump run on priming but it would never start. SO pump was good but probably not the valve. Now the pump does not prime with key in on position so I suppose....The things you find that previous owners do to cut corners. I know that sometimes funds are tight but that was not that guys issue. He had a monster stereo and the 20's you see on the picture on it. He just took shortcuts with the important stuff for the fun stuff. By the way those rims are off the truck!
Reading how much a pain it is to drop tanks.....OH the joy. I may leave the senders in since the in tank pumps are flow through. I may take the short bed off to get to the wires though. Hey at least I will have two tanks in the near future! The wiring is my nemesis. Deep breaths.

 

[AuroraGirl]

I know this thread is old. But thought if anyone looked at it......
I am in the middle of a TBI to carb swap. Talking amongst yourselves can begin. But I decided I want to not only swap but completely get rid of my computer and all the extra wires. I am going to run this universal 3 port selector valve by Tanks Inc. Electric Holley pump that is 4-7 psi so no regulator. I will use the dash switch to operate both the sending units and to power this selector valve. I will run the pump through both the oil pressure switch and a relay.
I took off the protective plate from factory to find the prev. owner had bypassed the entire 6 way valve. He had only the drivers tank going to the engine. I never was able to use the pass side tank because the minute I hit the switch it killed the engine. Well looking at the port he had a loop of tubing going from one side of the valve back around to the other side. I am thinking the pass side tank had been left in a loop inside the valve. I used to hear the pump run on priming but it would never start. SO pump was good but probably not the valve. Now the pump does not prime with key in on position so I suppose....The things you find that previous owners do to cut corners. I know that sometimes funds are tight but that was not that guys issue. He had a monster stereo and the 20's you see on the picture on it. He just took shortcuts with the important stuff for the fun stuff. By the way those rims are off the truck!
Reading how much a pain it is to drop tanks.....OH the joy. I may leave the senders in since the in tank pumps are flow through. I may take the short bed off to get to the wires though. Hey at least I will have two tanks in the near future! The wiring is my nemesis. Deep breaths.

use 2 3 port valves and use the 1980 delay wiring to keep them from wearing out prematurely

youre welcome