I will provide further first hand back-up of the existence of factory provided Carter conversion kits for the Holley 4160 applications, performed the conversion many times myself during my time at dealers back then. They were packaged as complete kits, fuel lines, choke springs, any other hardware required, fully covered if under warranty. Installed correctly, appeared completely factory installed. Can’t tell you just how many 4160’s wound up in the trash, considered pure junk then by those who serviced them and many under hood fires were blamed directly on them.