ok, let me restate that. when I took the rear pump off of the stock one there was a steel plate between the pump and the housing which made the pump obvious. howeve when I removed the rear "pump" from the modified one there was a gasket. the noticeable difference was at the bottom. the steel plate had two large port holes one each side of center. the modified had only one large port hole in the gasket to the left side of center, I did not remove the gasket because I did not hav an identical one in the kit. I assumed this was a modified part. it was lighter and thinner I believe, but outside looked the same. it may have been a pump. the housings looked the same.