How To Identify SBC Cylinder Heads | Infographic
Identify Small Block Chevy Cylinder Heads
To determine what type of heads are on your small block Chevy, take a look at the illustrations below for 'Early' or 'Late' Style, Aftermarket Aluminum SBC heads, Aftermarket Cast Iron heads, and other SBC cylinder heads. Text descriptions of the heads can also find text descriptions for each head type under the respective headings. Knowing the heads you have will help when it comes time to pick your alternator and air conditioner brackets. The illustration below is viewed as if you were standing at the front of the engine, as are the text descriptions.
Early Style Cast Iron SBC Heads (1955 to 1968)
These types of heads were used from 1955 thru 1968 and had no factory-drilled accessories holes on the face of the heads.
Late Style Cast Iron SBC Heads (1970 & Later)
These types of heads were from 1970 and later, and have 3 factory-drilled holes on the driver side head (with 3 5/8" inches between the top two), and 1 hole on the passenger side head.
Aftermarket Aluminum or Cast Iron SBC Heads
These types of heads will have 3 factory-drilled holes on the driver side head, and up to as many as 5 holes on the passenger side head. The most common dimension include: 3 5/8" between the top 2 drivers side holes, 3 1/2" between the top 2 passenger side holes, and 4 3/16" between the top left corner and bottom right corner passenger side holes.
Corvette & ZZ to ZZ4 Aluminum SBC Heads
These types of heads will have 3 factory-drilled holes on the driver side head, and 2 or 3 holes on the passenger side head with shared dimension on top holes to 'Aftermarket Aluminum or Cast Iron' heads.
Vortec Cast Iron SBC Heads
These types of heads will have 3 factory-drilled holes on the driver side head, and 3 holes on the passenger side head with 3 5/8" between the top driver side holes and 4 3/16" between the top passenger side holes.
Fast Burn Vortec Aluminum SBC Heads
These types of heads will have 3 factory-drilled holes on the driver side head, and 3 holes on the passenger side head with the same dimension as the top two holes on both sides of the 'Aftermarket Aluminum or Cast Iron' heads.