Stock number and how I measure my mounting position on the Super Mafia body.

This will mount the body about 4mm forward from center.

The measurement on wing perch is the same for the RCMaker Pro-Light HRB mount.

The excess plastic gives you about 13mm of run which was intentional from manufacturer. I cut mine down to about 3.50mm for desired clearance in front and 8.50mm on both sides.