What are the casting numbers on Chevy double hump heads?
What are the casting numbers on Chevy double hump heads?
Casting numbers typically had seven digits, and heads were commonly recognized by the last three numbers. Heads with tall casting marks were identified as 291-, 461-, 461X- and 462 castings and did not have accessory bolt holes.
What’s the difference between 461 and 461x cylinder heads?
The chamber shapes found on the 461 and 461X heads are not the same as those found on the 291, 462, or 186 heads. The 461X castings are popular for racers because they actually had slightly larger port volumes as cast than the 461 and other production heads.
What was the difference in cylinder heads in 1959?
The top two bolt holes were closer together than the lower bolt holes. Valve covers were made with bolt holes to match. In 1959, the valve cover holes in the heads were changed so that the holes were the same distance from one another across the top when compared to the lower holes.
What kind of head does a Chevy engine have?
General Motors identifies its small-block Chevy cylinder heads with both casting numbers and casting marks. “Double-hump” heads were found on many of its high-performance engines in the 1960s and early 1970s. They were manufactured with larger intake and exhaust port volumes and valves for the period,…
Casting numbers typically had seven digits, and heads were commonly recognized by the last three numbers. Heads with tall casting marks were identified as 291-, 461-, 461X- and 462 castings and did not have accessory bolt holes.
The chamber shapes found on the 461 and 461X heads are not the same as those found on the 291, 462, or 186 heads. The 461X castings are popular for racers because they actually had slightly larger port volumes as cast than the 461 and other production heads.
The top two bolt holes were closer together than the lower bolt holes. Valve covers were made with bolt holes to match. In 1959, the valve cover holes in the heads were changed so that the holes were the same distance from one another across the top when compared to the lower holes.
General Motors identifies its small-block Chevy cylinder heads with both casting numbers and casting marks. “Double-hump” heads were found on many of its high-performance engines in the 1960s and early 1970s. They were manufactured with larger intake and exhaust port volumes and valves for the period,…
