800hp is a bunch, the Torque is sometime the biggest factor though... I guess if you can fab some of your own parts you could, the converter would be most of all that money dosen't leave much for the trans, even if that dosent include the converter unless the guy make or fab's his own stuff, drums, bands, clutch materials & metals, bolt in sprag/overrunning clutch, manual valve body or trans brake, hardens input & output shafts, hardened front pump gears, hardened or better planitary gears, servos or eliminators, saftey shied or bell housing, deep cast aluminum pan & filter extension, misc hardware & gaskets it would be near impossible at least in my mind, unless the guy machined his own pieces & just bought the hardware, gaskets, o-rings, clutches & bands.... It's just my opinion some of those parts are that much money for a single part sometimes, you can check out some of the guys I've used in the past, Coan Racing Transmissions, Cope Transmissions, A & A Transmissions, Grinner Engineering, Turbo Action, Hughes Transmissions, B&M Racing Transmissions, TCI Racing Transmissions, Mikes Transmissions, Mancini Racing, Campbell Enterprises & Phoenix Transmissions amongst many others out there I sure...