If it is the early style like the ones from 64-66, it is being held up by 2 hook shaped wires. In the included pics are the 2 style drivers side boxes that I'm aware of. On the left is the above mentioned later style held up by the 3 mounting studs. on the right is the early style with the 2 bale wires to hold it up. Included is a picture of the bottom of the early style.
On the early style, the wire has a flat coin that is trapped inside the box by a couple flanges that are supposed to keep it from turning while you are loosening the bolts, which are accessable on the bottom. What happens most of the time is that the bolt seizes because of water getting in from a rusty cowl bellflange, and when you try to remove the bolt, it rips apart the flanges, which are just plastic tabs.
The best way, which is often not possible, is to open the door, clamp a pair of visegrips to the rod to keep it from turning and then remove the bolt. A shot of penetrating oil will help here also. Unfortunately, the bigger problem is that the same water that gets in to the box also rusts out the lower hinge and the door will break at the lower hinge pivot.
If I were going to remove an early air box, I would certainly start by hitting the lower hinge with some penetrating oil at least a week before I was going to try to remove the box, then spray it again. Then, slowly try to open the door, working carefully and in small increments. As the lower hinge starts to loosen up the door will open further, and eventually open enough to get a pair of vise grips in to remove the box. Due care with the hinge cannot be stressed enough, because if you break that lower hinge, its about $100 to find a decent box with a good door, and maybe a year or more to locate one!!!
Included are some pics to tell the difference, and to show what you are up against since none of this is visible when the box is in place!! good luck and take your time and save that door hinge!!! Geof
