I run heavy E rated 10 ply 34" M/Ts. The tire just fits. When the door is shut, I cannot slide a finger between the tire and bumper. The weight is noticeable when opening and closing the door. I always walk the door open rather than just let the door swing open and stress the parts when it reaches wide open.
I tried flipping the carrier and it didn't improve clearance at all. I stacked some fender washers under the two lower mount points and it helped a little bit. My tire still rests on my Demello bumper, but I'm fine with that. In my mind it relieves some of the stress on the rear door.