I got a Granatelli Motorsports Diablosport Predator for my 01 Tahoe 5.3 and it rocks! Plus, after I inquired, Diablosport sent me a new customized power program update via email for free. It also firmed up *and* quickened the shifts (user programmable), plus there is a separate program for the Tow/Haul mode. Got it brand new from a guy on ebay, so saved at least 150. Highly recommended. Oh, and I get no pinging with the power program but I always use 93 octane.