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Engine Identification

Engines are identified by first two letters in production code number, located at left side of block, below front two spark plugs (350" engines) and on left side of block below rear two spark plugs (455" engines). Code letters are as follows:

Engine Code Letters
350" 2-Bbl. XC
350" 4-Bbl. XB
455" 4-Bbl. XF
455" 4-Bbl. Stage 1 (Century) XS
455" 4-Bbl. Stage 1 (Riviera) XA