The clutch pedal in my 1986 SE V6 used to squeak. Not loud, but noticeable.
Installed a pair of Rodney Dickman's bushings, changed to steel pedal (eliminated return spring), bushed pin for the banjo per instructions on V8 Archie's website. After doing all that, was rewarded with - silence! No squeak
!
Don't know exactly which of the above tasks killed the squeak, but it doesn't matter. Had to remove the pedal anyway, so figured might as well rebush with Rodney's bushings. Old nylon bushings had obvious wear. New pedal installation is nice and tight (nearly no slop), so I'm pleased.
BTW, since the old pedal had squeaked for quite a while, bet I tried to lube it a time or two. Might have contributed to the destruction of the old bushings, as theogre mentioned. Oh, well - now I know better 
Incidentally, Rodney's online catalog indicates brake pedal bushings are same as for clutch pedal, as pointed out.