1968-1972 Corvette Exhaust Manifold Casting Numbers

1968

Left Right Engine
3872765 3872778 All 327 Engines
3880827 3880828 All 427 Engines

1969

Left Right Engine
3872765 3932461 All 350 Engines
3880827 3880828 All 427 Engines

1970

Left Right Engine
3846559 3932465 Early 300 & 350 Horsepower Engines
3846559 3989036 Late 300 & 350 Horsepower Engines
3872765 3932461 370 Horsepower LT1 350 Engine with AIR
3969869 3880828 390 Horsepower LS5 454 Engine

1971

Left Right Engine
3846559 3989036 270 Horsepower 350 Engine
3872765 3932461 330 Horsepower LT1 350 Engine with AIR
3880869 3880828 365 Horsepower LS5 454 Engine
3880869 3880828 425 Horsepower LS6 454 Engine with AIR

1972

Left Right Engine
3932461 3989036 Early 200 Horsepower 350 Engine**
3932461 3932461 Later 200 Horsepower 350 Engine**
3932461 3932461 255 Horsepower LT1 350 Engine with AIR
386711 386711 255 Horsepower LT1 350 Engine with AIR
3969869 3880828 270 Horsepower LS5 454 Engine with AIR

** Manifolds not drilled for AIR System except with NB2 (California) Emission System.