Rocketbrian

Yesterday on my 71 SX I removed two pieces of angle iron that were welded to the frame and bumper brackets by a past owner for purposes of mounting a trailer hitch. Apparently before that route, the morons used the rear cross member to attempt to tow something and pulled the crossmember down bending the body mount bolts and preventing the bumper from being able to be fully raised into position. Now I am in the process of replacing the mounts and bolts and will be replacing the rear crossmember with a reproduction piece. Of course the nut spun for the right mount bolt and I suspect the same will happen to the left one necessitating a hole to be cut in the trunk floor.
It would seem the hole must be cut in the sloped part of the trunk? For those that have done this what did you do and what size of hole is best to get a good grip on the nut? Suggestions?
Some pictures for your entertainment.

joe_padavano

The path of minimum damage is likely to cut the head off the bolt, cut a hole in the trunk floor, and extract the cage nut and remainder of the bolt that way. As for the other side, drill a small hole in the trunk floor above the nut and liberally apply your favorite penetrating oil. Also, always use an impact wrench to remove these bolts. This seems to help break the rust loose.

Rocketbrian

Thanks Joe. I would have forgotten about the impact wrench. Appreciate the reply.