Measurement between the threaded brass inserts in the legs is exactly 4 center to center. The most popular measured 4-1/8" center to center
Inlet & Outlet measures 3 inches OD
Non-returnable item except for warranty issues
There are two different 56 frame sizes in the FMXP2 series, please use the guide below to confirm the size you have.
to find out what frame size your motor is.
for more Aqua Flo FMXP2 56 Frame Parts and Wet-Ends.