Just curious, has anyone done this on a magnum motor? I am researching this for my 2000 Dakota. I know they finally make a standalone TCU. The swap would make a world of difference vs the original in terms of performance and mileage. Going from the 46RE with a 3.90 gear, the 8 hp with a 3.21 would give a gear multiplication of better than a 4.88! And the RPM drop at 60 and 70 mph is awesome!