Werner,I am buiding a 425 also...Contact Carmen at J&C Parts 7127 Ward Rd,Tonawanda,N.Y. Phone 716-693-4090/fax716-695-7144 I was at his place and he has everything almost for a nailhead Buick.He has original carbs but I do not know how much.let me know if you find out.I am looking for an original or aftermarket standard bellhousing..E-Mail.... jamesr@sympatico.ca Goodluck and Regards...Jim