hey hey. found this.
http://67-72chevytrucks.com/vboard/s...d.php?t=363854
wish I had my spid but it mentions the tank switcher beside the seatbelt which is where I had mine. And i have a hole in my dash which i now think is for the switch to change between sending units.
now that is cool.. 2 tanks using the same gauge.
So now I know(think) its a factory tank.
maybe I can find the sender/pickup.
thanks for pointing me there.