I've done a search but I haven't seen much about what everyone thinks the best CAI is... I was thinking about buying a K&N 63 series. Shows a dyno graph of a 11.9 whp gain on a '05 5.3l. Does anyone have any experience with these?

 

I think they're pretty much the same. I have the Vollant and really like the fit/finish. The outlaw i've seen looks pretty darn good too. As long as the enclosure provides a barrier to engine compartment heat and the filter and tube flow well, you should be fine.
As far as claimed HP? That's another story.

 

I like the outlaw. Thats what will be on my truck later today.

 

1st thing to do is ignore the hp claims.

2nd - alot of people are using a drop-in filter in a modified stock box with a home made replacement tube

 

i have a mutt intake and love it. factory lower box, upd lid and tube with a volane ram air setup.