The guys at MV automatics claim that they have seen many automatics with their shift kit and trans cooler cope with 300KW (for the long haul not just a month or two). For the guys with manuals, lets see you do this without going through a few heavy duty clutches, and/or rebuilding the box. IMHO the auto is every bit as strong as a manual, and a dam site cheeper to rebuild/repair in the long run.