You will have little luck. With the F201 Diffs (Evo III and IV also) the diff screws are very very brittle. I know that the lightweight ball diff for the F201 comes with 2 screws with a reinforced section at the top of the screw to stop the breakages that affected the std diffs in the 201. You could check those out. I know that Metro Hobbies has stock of them fairly regularly due to me and a mate of mine constantly hassling them for availability. Unfortunately that would mean that you'd have to buy the entire lightweight ball diff set for the F201 (39 from metro by memory), but even so, check em out, just make sure the its the right length. Its like 2x15 I think, but check it out still.