ill agree its involved, but its been done. i kid on here has done it as well, and on the ls4 aftermarket being tiny i guess ls4 specific aftermarket is small but the lsx engine platform aftermarket isnt. so most lsx parts will work. ive said it before though when you get to the point of doing something like this i think it would just be more cost effective to sell your current car and buy one with the drivetrain you want in it.