Questions for the guys running 33's

Really I just want to know what is necessary to run 33's on our trucks. I'd rather not do any major trimming or modifications. If I could get a 3" front spacer lift and a 1.75" AAL would that be enough? I'm alright with going for a 32" tire if it's not possible with the small amount of above modification. Also, how bad is the power loss? I've got an auto, and I don't tow at all. I do light offroading, and drive on the highway around 70-75 pretty often. Will I NEED a re-gear? Or could I get away without it for a while. I will eventually do it, just not yet.