The Ford Inline Six 200 first appeared in 1963, and can be identified by three freeze plugs located on the side of the engine block. The Inline Six 200 had the original four main bearing design inherited from earlier Ford engines, like the 144 and 170 cubic inch Ford engines, and was only included with the Ford Fairlane.
In August of 1964, the Ford Inline Six 200 was the standard engine included with the Ford Mustang--rated at 140 hp @ 4,400 rpm with 190 ft lbs of torque. It continued to be used in the Ford Mustang as the standard engine for seven years until replaced in 1971.
The first version of the Inline Six 200 was used until beginning of 1965, when the four main bearings were replaced with seven. Increasing the number of main bearings decreased vibration and made the Ford Inline Six 200 a much stronger and more durable engine. Three freeze plugs on the side of the engine block were also increased to five. Use the casting code “C5DE-H” to identify an Inline Six 200.
In 1966, a six bolt bell housing flange block was added to the Inline Six design--staying consistent in this form until 1980. During that year, designers put a new bell housing flange on the Ford Inline Six 200 called the “Big Bell 200.” They also moved the starter down to the bottom of the engine by the oil pan rail. The 1980+ version of the Inline Six 200 is popular with Inline Six enthusiasts since it can be adapted for use with a Ford small block V8 six bolt bell housing.
The Ford Inline Six 200 was included with Ford Maverick, Comet, Fairlane, and Mercury Zephyr, until most of these cars were discontinued in 1983. The Ford Inline Six 200 was included with the Ford Granada and Mercury Monarch from 1975 to 1982, which were subsequently replaced with the Ford LTD and Mercury Marquis. The Ford LTD and Mercury Marquis continued to be offered with the Ford Inline Six 200 until it was full retired in 1985, to be replaced by the 3.8L Essex V6.