You can't even get the hitch in the correct position on the van until you remove the flange that those 2 bolts use. The flange hits on the gray water tank and mounting. Without moving the tank, no hitch will bolt in and moving it would be a real pain, redesigning the entire drain system and figuring out where to remount it. Easier to cut off the flange. The mounting bolts supplied are grade 8 and you just have to be aware you lost some weight capability. I never planned on towing anything near the 5000 lb limit of the van, so I wasn't concerned with it. As with most things they build in a safety factor, if its rated at 6000 lbs it won't break at 6010 more like 7500 or higher.