He ran it with no axles so I doubt it could be the housing. This is frustrating for me too. Ha ha!! Can't even think of what to try next but it must be up front. What converter is in it now? the stock one or your good one? What about running it with the converter unbolted, are you absolutely sure there is no engine vibration. I thought the B&M plate with the section missing was for a 360 with weight on the converter but You had a balanced converter did you not?