Nice, thanks guys. Yeah the weight balance L/R seems fine, no major difference than my M03 which never had issues like this. Was thinking torque steer but why would that be different than the M03 too?
I 100% agree that it's a driveline problem, definitely going to look into the spline issues, it is a brand new diff (TA03) and brand new universals but that sounds totally feasable.
I'd be shocked if it was the bearings as again, brand new and i removed one side of the shields and blasted them/oiled them but you never know. I've only driven it in an open lot for now, so there havent been any collisions (yet) to blow any bearings.
I had thought that maybe something was screwy with the steering rack as there is a lot of slop in it but those suggestions sound like great starting points.
thanks again for all the help.