I have a 2007 Silverado 2500HD that I pull a travel trailer with and would like to install a transmission pan with extra capacity. I have looked at several but I would appreciate any input from Silverado owners. B&m seems to be the only one that will fit because of the smaller height of the pan at the rear. Derale makes a nice looking pan but not sure if it will fit. Also what is your felling about Mobil 1 atf?