I added fuel tanks to a 72 K10 that I had. Built saddle tanks with a fill neck in the front of the wheel well and stuck a Campbells soup can over the neck and cap to keep the crud off.

Here is a solenoid operated switchover valve from Summit Racing.

And here is a manual valve from Amazon (probably available other places as well - try a marine store like West Marine.)
That last valve was just like I the one I used on the K10.

Last edited by klhansen; 10/16/2024 5:42 PM. Reason: added more info
Kevin
1951 Chevy 3100 work truck
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1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car)
Busting rust since the mid-60's
If you're smart enough to take it apart, you darn well better be smart enough to put it back together.