I bought this kit because I don't seem to have them on my car. What are they exactly used for? Which holes did they go in? Any help would be appreciated..
http://69camaro.nextmill.net/temp/wellnuts.jpg

The radiator well nuts go on the drivers side of the rad support, there are large holes that they go into. As you tighten the small bolts they expand and stay in the holes. There are 2 sets of holes on the drivers side, the outer set is for a 396/427 rad or maybe small block HD rad, the inner ones are for a 302/350 or small rad. The passenger side uses the conventional bolts, that thread into the rad support.
The reason these are used is so that the radiator has a flexible mount so the core does not shake apart from vibration or bumps etc. Hope this helps.