which modifications eliminate the engine's "water deck" and substitute a "water manifold", as well as 567C and 567D engines, may be upgraded to use 645 power assemblies, theoretically achieving an increase in horsepower, but not without corresponding changes to the engine's Woodward governor which activates and controls the engine's "fuel rack". Although this power increase is not recommended, horsepower-for-horsepower updates (e.g., 567D to "645D"—645 power assemblies in a 567 block) are quite successful and common. As 645 power assemblies are more readily available than 567 power assemblies, this upgrade may also be employed in so-called "life extension" programs, in which case the power assemblies would be upgraded, and the engine may be de-turbo-ed, without corresponding changes to the engine's Woodward governor, hence without a corresponding power increase. Because of their age, 567 engines are generally exempt from emissions rules. EMD manufactures a special series of 645 power assemblies which are particularly useful in updating these exempt 567 engines and also certain exempt 645 engines. Versions Numerous early improvements were aimed at increasing reliability and life, including a switch from the "U" shaped top (exhaust) well to a "V" shaped top well. This eliminated the cast top deck, which had been the source of some early-life failures, in favor of a top deck fabricated from plate steel. The 567 gave way to the 567A in 1941, which incorporated further top deck improvements and camshaft gear train changes. The 567B followed in 1946 with minor improvements. The 567C was released to further improve reliability and manufacturability. Visually, the 567C may be distinguished from earlier models by the presence of round (instead of square) handholes. The cost of a 16-567 in 1941 was US$24,000, and a 16-567B in 1951 was US$32,905. Stationary/marine versions Like most EMD engines, the 567 was also sold for stationary and marine applications. Stationary and marine installations were available with either a left or right-hand rotating engine. Marine engines differ from railroad and stationary engines mainly in the shape and depth of the engine's oil sump, which was altered to accommodate the rolling and pitching motions encountered in marine applications. 567 locomotive models An EMD locomotive catalog, contemporary with the 567, lists the following models: Most 567C locomotive models used D37B traction motors until mid 1959 when the D47B traction motor was used in production locomotives. Very early 567C locomotives from 1953 used the D27B traction motor. 567C and