[BryanLZ]

There is what looks like a cable pulley behind my drivers side inner fender. There is nothing attached to it and it makes quite a nice rattle while going over bumpy roads. What purpose does this serve?

 

[jimcg]

Could it be the parking brake wheel? Look at this picture:
http://www.trifive.com/garage/55 Chevy Assembly Manual/5-5.gif

 

[BryanLZ]

I should have clarified; it is behind the inner fender on the front drivers side.

 

[BryanLZ]

After looking at that picture a little more closely, I think your right. That must be what it is for.

 

[angs1957]

The only pulley there is for the parkbrake assembley as jimcg as suggested