Hi Roger,
Nice to hear from you. I was not implying that all is a direct correlation, only that based on the Burlen database that some of the HV numbers correspond to the later H numbering based on replacement throttle plate kits and that there is a one number offset in this correspondence. Also, the pictures shown are of the OM type carbs vs. the HV type. Please correct me if I have misspoken.
Regards,
Fred