Is this rule change discussing the holes that the motor mounts plug into on the front sub frame?
9.1.7. Spec Miata (SM) SpecificationsGCR - 580
t. For purposes of making engine installation easier, it is permitted to create a vertical slot between
the top 2 factory mountingholes on the driver’s side of the subframe to match the existing slot
on the passenger side. The subframe is comprised of a topand bottom layer of sheet metal. The
only modifications permitted are to the top layer of sheet metal to match the bottom layer of sheet
metal which is already slotted. The slot may only connect the two existing holes and shall not
exceed the width (.43”) or height of the existing OEM holes. No material may be added.