What are Snowflake heads?

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The Bowtie heads were an over the counter head offered from Chevrolet for racers. These were a revised version of the older factory offerings. I believe that most, if not all, of the factory offered aluminum heads were cast at the Winters foundry. Hence the “Snowflake”.

What are peanut port heads?

For the uninitiated, peanut port refers to the small, oval-port heads used on the Gen-V 454 truck motors run prior to the introduction of the Gen VI in 1996.

Are all big block Chevy heads the same?

The only OEM blocks with these bosses were the rare ZL1 aluminum blocks, but many modern aftermarket blocks have this added feature. Mark IV, Gen V and Gen VI heads all have the same head bolt pattern, but they are not interchangeable due to different water jacket cooling passages.

Where are the casting numbers on a big block Chevy head?

However, the complete casting number is located beneath the valve cover, usually above an intake port. Additionally, either the last three digits of the casting number or the complete number can usually be found beneath one of the intake ports when a head is viewed from the combustion chamber side.

What are 781 heads?

The 781 heads are the best cast iron large oval port heads GM ever produced for the big block Chevy engine. They are worth rebuilding and respond well to pocket porting, bowl blending and larger valves. They will easily support over 500 horsepower. They are a very desirable street head.

Which is better open or closed chamber heads?

Open and closed chamber cylinder heads differ in combustion chamber capacity. Although open chamber cylinders offer easier flow, the closed chamber cylinder is better for performance. Compression ratios are also affected by the size of the chambers.

Can you put 396 heads on a 454 block?

For example, tossing a set of 454 open-chamber heads on a 396 could radically reduce the compression ratio because of the roughly 10cc larger chamber on a short-stroke engine. Production big-blocks all the way into the mid ’90s were always flat tappet camshaft engines.

Where can I find head casting numbers?

HEAD CASTING NUMBERS The head casting number is located on the top of the cylinder head. The valve covers must be removed to find the number.

Are BBC 781 heads good?

Are 781 heads open or closed chamber?

Are 781 heads open or closed chamber? The ‘781 is the best choice for a 396 because it has the smallest open combustion chamber to help with static compression.