hello mate ive got the whole BC valvetrain, i also looked at the keepers/collets and BC only listed them for the Nissan SR20 engines, i have already tried the oem keepers and they fit perfect.
my head will be back from the machine shop on saturday after being skimmed and then i will be assembling the head, i will let you know how it go's.
i will try and get a pic up tomorrow/later today of the keeper and retainer.