The newer vehicles with 6 or more speed automatics are light years above the older transmissions. I know this is sacrilege for the TH400, C6 and A727 crowd. Honestly, the engine and transmission improvements in the last few years beat hands down any mods you can make to an older vehicle. The new computer controlled variable valve timing motors put out more torque and hp...Our work trucks are E350 cutway vans, the 2009's had the 2 valve 4.6L and 4 speed transmission, the 2010's with 3 Valve 4.6L and 6 speed transmissions were a whole different animal.