I'm in the process of doing a 440 into a 70 Duster with the Shumacher convertion mounts. I found the exact same problem. I forget the number on the stock pan but it is out of a 74 C body (Imperial). I wound up going with a Milodon pan I had. The milodon looks like the same one in Womanators photo. Insted of notching it like Womanators, I simply heated the area a little with a Mapp gas torch and gave it a little work with a ball peen hammer. The rail did not distort at all and it still clears the Milodon windage tray fine. It now clears the center link no problem. One other thing I did was to cut a small notch into the K frame on the passenger side to make removing and installing the engine with the trans bolted on easy. Without the notch the sump would interfere with the K frame and make the intall more difficult. You could probly heat and dent the stock pan also.