In '67 they were called Custom.. I think I read somewhere that the "CST" designation started in '68 or '69.
The '67 Custom in my lawn at the moment has a solid metal floor in the bed, carpet in the cab, chrome bumpers (front and back), rear coil over springs, bucket seats (not sure if they're original) a big back window (not often found before 1968) and what i'm told is a rare "max speed buzzer".
I really don't know what the "base" Custom/CST package was.. from my understanding you could get quite a few options put on one of these trucks. Factory options are listed on a sticker found on the inside of the glove box door.
