Ответ:The 666-660 kit was introduced in service bulletin A11-62. The kit (and service bulletin) allow for modifications to be made to 10-3878 carburetors to realize ?improved performance?. Service bulletin A11-62 applies to part number 10-3878 carburetors installed in select Moony aircraft with specific engines. Later, service bulletin A3-63 allowed for the same modification to be performed on 10-3878 carburetors installed in Piper Cherokee aircraft.