[CR]8-spd pulleys in 6-spd derailleurs

hi,

has anyone tried to use these 8-speed campagnolo pulleys in on-topic derailleurs? i know there are more accurate repro parts available for campy at least, but these are half the price and would get some of my stash of incomplete rear der's back on the road before they're further cannibalized:

http://www.probikekit.com/display.php?code=a8040

thanks,
randy dugan
van nuys, ca usa