Like I said more expensive. Wrench and weld? You mean you need a full service shop with a lift. The average Joe aint swapping a 12 valve in to their 6.4 F250 in their driveway. Trust me I've owned quite a few diesels, even bulletproofing a 6.4 or 6.0 is no easy task for the average Joe.
Kids are cummins swapping fords in there carports now a days.