This has probably been covered a million times before, but, what is the difference between the two. I am new to this having always driven gassers, I just bought my 07 ccsb LBZ w/ allison saturday and am trying to pick the best one. I want something that is gonna be safe and undetectable if I have to take it back to the dealership. I am looking for a decent power increase without putting my truck at risk. Any help would be really appreciated. Seems like most people I have talked with say either one or the other but what's the difference. Thanks.