Make sure the engine is mounted correctly and centered. Another CEG'er had stripped his axle shaft from that! (Try posting in 3.0 forum, others there have your LS diff.) I have read the new and very nice

Acura TL has some odd torque steer with a limited slip, sounds similar to what you get. Regular torque steer is to the right (my SHO). Alignment is really important, too much toe out will make your car loose and less stable. The 3.0 is stronger torque, (which you should be enjoying!)