04 Silverado Leveling?

[SSSilverado23]

I want to level out my 04 silverado 1500. I know you can crank the torsion bars then get an alignment. I talked to my local les schuab tire center and they said that if they did it and or when the did the alignment they would put it within factory specs which is 1.5'' of raising. Is there a way to get anymore than that or what should i do? Is 1.5'' about right? Is there another way to level it out? Let me know what i should do or how to go about this. Thanks for all the help!