Took the truck in to a local shop. Fuel gauge is maxed out on fuel.
They said did some test and its a bad fuel sending unit. The shop
looked on the internet and could not find a replacement unit.

Where can you get a replacement unit.

Truck has the opt 22 gallon tank, and 90 ohm full and 0 empty

I found, the last one in the country, fuel sending unit through local Chevy dealer. Was last one in stock, for a 17 gal. tank, in Flint Mi. cost $160.00
Try them first.
If not, I have seen them on E-Bay for approx. $120.00 for a 22gal. tank.

Thanks for the imformation and link, Gonna give them a look