2002HD Inaccurate Fuel Gauge/Circuit Breaker problem

The fuel (http://www.chevroletforum.com/m_2433/tm.htm#) gauge is reading more fuel than is actually in the tank. And by the time my fuel light comes on I have about 2-5 miles before the "ECM B" 20 amp fuse pops, killing power to my fuel pump and bringing the truck to a stop. This has happened twice so far. Now I just fill the truck up once it reaches about 250 miles on my trip to keep this from happening again. My friend told me that the fuel pump and the fuel quantity system are the same part on this truck and that it needed to be replaced. I think he called it the "Sending Unit"? Does my friend know what he's talking about or do I need to look into something else? Any help would be greatly appreciated.

Brewser

The sending unit can be purchased seperately from the pump.