One new replacement muffler to fit Massey Ferguson tractors models 50 (GASOLINE OR DIESEL ENGINE – USED AS VERTICAL OR HORIZONTAL), 65 (GASOLINE OR DIESEL ENGINE – USED AS VERTICAL). Vertical or Horizontal/Round Body – 3 1/4″ Shell Size Dimension A (1) A: 2 3/4″ INLET LENGTH Dimension B (2) B: 1 3/4″ INLET ID DIAMETER Dimension C (3) C: 20″ SHELL LENGTH Dimension D (4) D: 11″ OUTLET LENGTH Dimension E (5) E: 1 3/4″ OUTLET OD DIAMETER Dimension F (6) F: 34″ OVERALL LENGTH Replaces part number 187184M1. Reference Numbers: 187184M1, 187184M91, 187184M91-A