I have a 2002 Silvarodo LS SB with 5.3 It only has 43,000 miles on it, but I'm having to add Daxacool at an icreaasing rate. I bought it new so I know that the oil was changed regularly. I don't see any sign of coolant on the block or driveway, so i guess its burning it?? bad gaskett?

 

Most likly a bad gasket, you might want to check the oil, maybe some of it leaked into it.