Ron,
Our ULTRA BREEZE is mounted on the center line of the roof, midway between the Dometic a/c unit and the rear end of the PC. It is difficult for me to make an exact measurement of either one, but they both stand very close to 11" above the roof. From the photos of the PC on the website, the roof seems to slope downward a little toward the rear, so that would indicate that the top of the vent cover would be slightly lower than the top of the a/c unit.
--Bruce