A problem I have read about on another site was the crank thrust surface finish was not smooth enough causing excessive ware. I dont think many machinist really look at that surface at all when they polish/refinish a crank. This a a prob with many 5.0 ford racers from what I have read. They resolved the prob by using a much finer polished finish on the thrust surface. Is it a 4sp or auto?? Another 440 locally here had the same problem after a few hundred miles. Let us know what your machinist says.