Just in case I want to pursue some crazy ideas----Are the 4 and 5 cylinder diesel engines the same except for obviously the number of cylinders? I know there were some internal changes to deal with the extra heat and power from the turbo, but aside from that how similar are they? Specifically, does anyone know if the bolt centers and the valve port spacing are the same for the two engines? The crazy idea would be to rework the intake and exhaust manifolds from the turbo motor to fit the 4cyl. I would think limiting boost to 4 or 5 lbs would add a few horses without adding too much strain to the engine internals.