2005 Silverado HD 6.0. Same problem as alot of other people. Gauge does not read right. Replaced fuel send unit. Has all the right voltage readings at the pump. Problem is the gauge is still not reading correctly. Empty when full etc. Anybody else have this problem. Thinking it might be the gauge itself. How hard to replace and any way to test it. Does this come as a cluster or what any help out there Thanks