Exhaust Manifold Casting Numbers

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Big block V8: 396, 402, 427, 454
Small block V8: 265, 283, 302, 307, 350, 400

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>> 1965 - 1972 Chevelle Specific

These exhaust manifold castings were used in various other models of the Chevrolet lineup such as the passenger car, Chevy II/Nova, Camaro and Corvette. Only Chevelle-specific information is listed here to conserve space. Some casting numbers are NOT listed as they may have been used in other models of the Chevrolet lineup but were NOT used in the Chevelle.

All factory exhaust manifolds are cast iron. Some may not have casting dates and the location of dates and/or casting numbers may vary from year to year.

It's important to remember the 'to' and 'from' dates listed may vary due to production lead time and stock inventories being depleted. For example just because a particular exhaust manifold casting may be listed as being used from January to April doesn't imply that the engine assembly plants discarded all pre-January exhaust manifolds or on the 1st of May discard all exhaust manifolds they had in inventory to begin using the newer design. Many manifolds were used in multiple years.

Exhaust manifolds are normally date coded in the form of a letter for the month (see table below), two numbers for the day and a single number for the year. For example, C259 indicates a date of March 25, 1969.

Typical "log" style exhaust manifold for big block. On engine equipped with A.I.R., the small squares are drilled and tapped for A.I.R. fittings	Typical "log" style exhaust manifold for later small block.
Typical "ram horn" exhaust manifold for early small black with center dump.	Typical "ram horn" exhaust manifold for early small black with rear dump with front bracket for generator mounting.

1970 SS396/SS454 Atlanta/Baltimore/Kansas City/Van Nuys Build Sheet Decoder

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