Which LT Headers make the most HP and TQ?

[STEALTH 408]

I just got a 2002 Yukon with the 5.3,I want to do an air intake,pulley and a full exhaust from the headers back.Which headers make the most RWHP and TQ,I would think a 1 5/8 primary would be better for a stock heads and cam 5.3,I don't want to lose any bottom end torque.Does anyone make a true equal length long tube header?How long and big are the primaries on the Hamm's,ASM's'TOG's,anyone know?What type of gains have you seen with these headers?Has anyone seen a legitimate gain with any of the shorties?When I say legitimate I mean independent dyno and track testing,not what a magazine says.What's the most RWHP/TQ anyone has gained with headers and exhaust w/cats on a 5.3?

[BigKID]

Hamms have 1 5/8" primaries and ASM, TOG, and LaPoles have 1 3/4" primaries. I have a buddy with the Lapoles and I will have my Hamms some time next week. Once I get mine on we are both going back to the Dyno to see the gains each one made.

[y2kboti]

BigKID be sure to post the results. I am really interested in knowing what happens.