Sorry, just didn't think there was parts available to get the LS400 auto to handle big torque. I have dealt with the 4L80E with high HP/High TQ (over 1000 HP) and had no problems with it what so ever. I saw some articles about all the high HP Supra's running power glides or turbo 400's and now 4L80's so I figured it's an easy swap.
With mass experience with my Impala and 396 stroker/250 shot I ate up 4L60E trannies like they were candy so I started messing with the 4L80E's.