The diesel converter stalls a little lower than what would have come in that combination from factory. Even the factory converter stalls two low and makes the engine work just to pull away from a stoplight.

This past fall I rebuilt my 4L80E in the 98 K2500 because I broke the reverse band. I used a reman converter from a 99 G2500 van with a 4.3V6 and 4L80E. The converter code is B82. This is the highest stalling converter from factory for a 4L80E that fits the L31. You need the 6 Lug flywheel which you should be using anyway when swapping to the 4L80.

This was by far the best mod I have done to this truck. It gets up and goes at any speed and shifts and locks up perfect with the factory PCM and factory tune. With no codes.