I own a 1999 Durango, 5.2 liter, 4WD. The flange bolts are incredibly difficult to try and reach (yes, they are rusted as all heck). Should I consider removing the break master cylinder?

 

I always go from the bottom. After I got them out the first time, I welded a small bar to the top of the bolt heads to keep them from spinning as I worked from below. Now I don't have to reach up with a box wrench while spinning the bottom.

 

Nice tip, thanks. I managed to get the bolts out after hammering away at them with a crowbar positioned just above the nut. Turns out, however, I think I have the wrong-sized flange. I bought one for a 2-1/2" pipe, as advised by this board, but mine seems to be smaller.

Any idea what OD the exhaust front pipe is?