Fuel level sensor..

i would ask for help..
my Camaro doesnt show fuel level.sensor on desk it always shows full
i took it to my friend, mechanic for american cars, and he told me my car needs new fuel level sensor. the one thats in gas tank.
so.. anyone have any idea how much does it costs and where to find it?
Camaro is RS 1991. 3.2 engine, if that matters.

If it stays on full it could also be the wire going to it grounding some where or the gauge itself is bad. I would check the wiring first because its a pain to drop the tank for the sending unit.
http://prod.spectra-ssl.com/PROD/apps/eCat/v1.04.05/mainfile.php?vehicle_id=1035762&model=CAMARO&year=1991&make=CHEVROLET&action=search_by_vehicle&module=product_catalog&splash=false&APP_VERS=1.04.05
There is a part number for the sender from spetra. You can do a search with that number or check ebay, classicindustries.com, nextgen.com, auto wreckers.
I found a fuel tank for an S10 with the spectra part number and an internet search. But I would deffinatly check the gauge and wiring first before dropping the tank. And if you do change the sender change the pump at the same time.