if the frame is lower than the bumper, that is what they measure, according to what you posted:
(iv) The front and rear height measurements shall be made to the bottom edge of the foremost portion of the frame rail, or to the original mounting brackets, whichever is lower, if one of the following apply:
(D) The manufacturer’s specified bumper has been replaced with a bumper not identical to the manufacturer’s specified bumper.
this being stated, what is your frame height from the ground to the lowest point?
