For what its worth this is a 3 piece bottom bracket conversion I did on one of my 1973 SSs. It uses a standard BMX bottom bracket that costs $10 to $20 at most shops and includes new bearings and cups. It is designed to use a tapered 3 piece crank but the bearings are designed to fit standard frame size for a 1 piece crank. You just put it in the BB and bolt things up. No fooling around required. Roger