Bah, guess someone must have replaced them with something else!! I found what it is, btw. I went to O'Reilly parts and saw what I needed, even though I already looked; guess I just overlooked it. The bolt requires a triple square driver.

On a related note, one of the back bolts snapped off! I just finished drilling it out, and am about to go buy a through bolt and nut. It seems like on these cars, I'll fix one thing only to discover another problem.