Like a cap from a w-body Impala/MC from '00-to '06, or any other gm models.  I am looking to pick up a gm locking gas cap, and so far I haven't been able to find any for jbodies.  I am NOT interested in an aftermarket cap.  Thanks in advance.
 
Just go aftermarket and pay 15 bucks at Kragen/Shucks/Checkers, napa, autozone, etc. Worth the money. They work great. First "mod" i did to my car almost 45000 miles ago.
2004 Cavalier, 2.2L Ecotec
1965 El Camino, 396 BBC, 14:1, 800 BHP
 
Yeah. Any GM gas cap that does the 1/4 turn will work.