The Controlled Combustion System (CCS) system was introduced in 1968 on certain engine and transmission combinations where emission standards could be met without the added expense of the Air Injection Reactor equipment.

A thermostatically controlled air cleaner assembly along with special carburetor, distributor settings, and higher engine operating temperatures comprised the CCS system in 1968 and 1969. In the following years, the thermostatically controlled air cleaner, or carburetor heated air (CHA), was sometimes used independently of the other three factors - with or without special carburetor and distributor settings. Likewise, some engines featured the special carburetor and distributor settings, and the higher operating temperatures, but did not incorporate the special air cleaner.

This 1969 396cid/325hp engine has the controlled combustion system installed since it is an automatic transmission car; a manual transmission 396cid/325hp engine will have air injector reactor emission equipment. The same holds true for the 1968 396cid/325hp engine with automatic transmission.