Rock Auto should have the flex plate that he needs for whatever year his 5.9 is. I have a 98 5.9 from a 3500 stick truck, and will be going to an automatic also. They had the right flex plate, as does Advance, NAPA, and pretty much all the big players in auto parts. He will have to rat one hole out in the flex plate to get his 904 neutral balance torque converter to bolt up. From that point on, the torque converter will bolt up in any position.