What are these nuts and bolts from?

[blown motor]

I was just cleaning up some stuff in the basement and found these. They are obviously off my 74 Challenger, but where? I replaced bumpers a couple years ago, dash pad about 5 years ago, pins and bushings in door hinges and I think everything else I've done to the car has been smaller stuff. 

[anlauto]

Are they 1/4-20 or 5/16-18 ? Hard to judge size from the picture.

Either way...those are real common throughout an entire car, hard to say exactly where they're from.....I guess just wait and see what falls off

[Spikedog08]

I would think not to many have nuts on them . . . one of them has a larger attached washer?  Hmmm

[blown motor]

Are they 1/4-20 or 5/16-18 ? Hard to judge size from the picture.

Either way...those are real common throughout an entire car, hard to say exactly where they're from.....I guess just wait and see what falls off

Lol! They are standard 3/8 UNC thread.
It's got me wondering. I obviously cleaned them up and repainted them but then didn't use them. So did I replace them with something? Not my usual MO.

[anlauto]

If they are 3/8 then the answer is easy...They go on the front bumper brackets to hold the two halves together

[Spikedog08]

If they are 3/8 then the answer is easy...They go on the front bumper brackets to hold the two halves together

             

[blown motor]

Thanks Alan. I'll have to have a look at that. 

[blown motor]

I checked the car and the 74 Challenger brackets are different. No hole there for a bolt. The mystery continues.

[anlauto]

I guess a learned something today.... Seems odd though...

[blown motor]

The straight part of the bracket where it contacts the frame is longer and has three bolts.

[Roadman]

   Murray, for god sakes, there horderves. Grab a beer and enjoy them.          

[anlauto]

On the outer ends of the front bumper reinforcement bar, there are bolts that bolt the rebar to the bumper brackets. Do you have those bolts/nuts in place ?

[blown motor]

Yes, and they are the proper style bolt. Not a replacement.

[dodj]

hard to say exactly where they're from.....I guess just wait and see what falls off

This..

[GY3R/T]

 Heavy corosion on the two dog point bolts ( under chassis application ) No corosion on the nuts. Are you sure these were originally mated ?  Dog point bolts usually work with J or U-nuts.