Tapered hole major diameter is 3.500 inches , flow direction is from the outside in; cylindrical shape
NSN 6110-01-400-4207
NSN 5998-01-657-6387
NSN 5910-00-840-6217
NSN 5930-00-147-3054
NSN 6650-00-932-2048
NSN 6105-00-960-9879
NSN 6240-01-434-8083
NSN 5996-00-820-4703
NSN 6610-01-092-5375
NSN 5998-00-256-5117
NSN 5835-01-061-9434
NSN 5915-01-232-3387