Heater between manifold and carb (1973 F engine)

[slickrock]

OD of the header tube, but can you post a pic of where it attaches to the aircleaner? I used to do it with a cutoff wheel on a die grinder, but now I have a plasma cutter


Ed

Ed it isn’t a complete circle. It is more oblong. The vertical 2.25” and the horizontal is 2.50”. Pictures below.