1968-1972 Corvette Head Casting Numbers

1968

Number Engine
3917291 300, 350 Horsepower 327 Cubic-Inch Engines
3917292 350 Horsepower 327 Cubic-Inch Engine
3917215 390 & 400 Horsepower 427 Cubic-Inch Engines
3919840 435 Horsepower 427 Cubic-Inch Engine (Cast Iron)
3919842 L88 & L89 (Aluminum)

1969

Number Engine
3927187 350 Horsepower 350 Cubic-Inch Engine
3947041 300 Horsepower 350 Cubic-Inch Engine
3931063 390 & 400 Horsepower 427 Cubic-Inch Engines
3919840 435 Horsepower 427 Cubic-Inch Engine (Cast Iron)
3919842 L89 (Aluminum)
3946074 L88 & ZL1 (Aluminum)

1970

Number Engine
3927186 300, 350 & 370 Horsepower 350 Cubic-Inch Engines
3927187 350 Horsepower 350 Cubic-Inch Engine
3973414 370 Horsepower 350 Cubic-Inch Engine
3964290 390 Horsepower 454 Cubic-Inch Engine
3964291 460 Horsepower LS7 Engine

Note: The LS7 engine was not produced for retail sale.

1971

Number Engine
3973487 270 & 330 Horsepower 350 Cubic-Inch Engines
3993820 365 Horsepower 454 Cubic-Inch Engine
3994026 425 Horsepower 454 Cubic-Inch LS6 Engine (unverified)
3946074 425 Horsepower 454 Cubic-Inch LS6 Engine

1972

Number Engine
3973487(X) 200 & 255 Horsepower 350 Cubic-Inch Engines
3998993 200 Horsepower 350 Cubic-Inch Engine (unverified)
3998916 255 Horsepower 350 Cubic-Inch Engine (unverified)
3999241 270 Horsepower 454 Cubic-Inch Engine

Note: (X) indicates an "X" casting foundry proof mark will appear after the seven-digit casting number on later 1972.