The LBZ comes with the most hp and torque but the fastest at the track are the lly's if I remember right. There are more power options for the LB7 and LLY. The stock Allison with the LBZ is at about its limit on power so you can't add as much with out possibly hurting the trans.

 

 

The LB7 engines are king for hp and at the track. The LLY's are coming on strong with some turbo and fuel system options now. The LB7's are taking advantage of the fueling options also.

EFI Live can tune the 01 to 04.5 LB7's and 04.5 to 2005 LLY's for huge power.

The 2006 LLY and LBZ (they share the Bosch computer, versus the Delphi of earlier models) are bringing up the rear with only a few handheld programming options. Diablo, PPE and Bullydog currently. Edge has a Juice in beta for the LBZ.

The stock Allison is the limiter for all of them.

 

My bad...I didn't remember for sure. Since I bought my LBZ I have been pretty much only reading about the LBZ. I know I'm looking forward to the new Edge to come out so I can decide on what programmer to get.