In 1969 there were 859 Boss 429s made by the Ford Motor Company, two of which were Cougars for the Lincoln/Mercury Race Division. Each car had a manual transmission and no air conditioning due to under hood real estate. Some early models were known as "S" code cars due to their slightly different engine. The "S" code cars had magnesium valve covers. Also, the Boss 429 or "Boss 9" did not have traditional head gaskets; the 429 motor had O-ring heads which were known to be the weak spot on the engine.