Hello all. First time posting here. I am thinking of swapping the stock 3800 motor in the GT to with an L67 used in the GTP and then building that motor (if possible) to my desired 300 - 350HP. My questions are; 1. Do I need to change tranny/gears. 2.Will it bolt directly on with no custom mounts. 3. Is it even really worth the time and money?