Well I thought I had a section in my favorites about fuel selector valves but I guess I don't
But one thing I remember reading is that these valves oem are expensive if you can find them or something that is made to replace them. But I do remember possibly Ctubutis bringing up in a thread I was searching that there is a universal that someone did a write up on and how to make it work with our trucks.
I forget if I did the search here or in the 80-86 forum, but I would imaging the 80-86 forum, cause I think he is a gasser
Enjoy & Goodluck,
Devin