Where are the casting numbers on big block chevy heads

Where are the numbers on Chevy heads?

Head casting numbers and the head casting date are located under the valve covers, in the rocker arm valley.

How do I find my casting number?

These can be found on the block, cylinder head, transmission case, differential housing, and other cast iron parts. Depending on the make and model of your vehicle they can be located in different areas.

Where do I find engine block casting numbers?

How do I identify Chevy heads?

Chevy heads have often been identified by sight and most commonly by the different casting shapes on the ends of the cylinder heads. While these casting marks cannot tell specifics about the cylinder heads, they can help identify a performance head from a non-performance head.

Where are the casting numbers on a small block Chevy?

Where Are Chevy Small Block Casting Numbers Located? On a small block Chevrolet, the casting number is found at the rear of the block on the driver’s side (as is with Chevy’s big block engines).

How do you read GM engine casting numbers?

Read the next four digits in the code, which will be all numbers. This refers to the date that the engine was cast. The first two numbers are the month, and the last two are the day. For example, if the numbers read 0107, then the engine was cast on January 7.

Where is the casting number on a cylinder head?

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. Keep in mind that if you remove the valve covers, new gaskets may be needed.

What is a 202 head?

“202” refers to the intake valve diameter of 2.02″. Fords and Chevys usually don’t have an intake problem… they usually have an exhaust problem. … You can actually lose flow by installing valves that are too big for the combustion chamber unless they are un-shrouded.

Are all SBC heads interchangeable?

One thing to keep in mind, the Gen-1 and LT-specific heads are not easily interchangeable. Each will physically bolt up to the other engine, but the water passages don’t line up. The exhaust ports and exhaust manifold-bolt holes are in the same location.

Is LQ4 a cathedral port?

Cathedral port heads came on the original (Gen III) LS1, but were also used on the performance-oriented LS2 and LS6 versions. Cathedral port heads were bolted on literally millions of truck variants, which included (among others) the 4.8L LR4, the 5.3L LM7, and 6.0L LQ4.

What did LS 243 heads come on?

The 243 head came on the more powerful LS6 engine from 2001 to 2006, and was used in C5 Corvettes. Later engines like the truck-spec LQ9 and LQ4 used the exact same port design as the LS6’s 243 heads, but had 6 cc larger combustion chambers.

What is a casting code?

Casting means changing the data type of a piece of data from one type to another. … This code asks the user to type in a number, then doubles that number.

Are all 243 heads Cathedral-Port?

Essentially a 243 head with different casting numbers, the 799/243 heads are considered to be the top of the line, factory, cathedral-port offerings. … By contrast, the 823, rec-port heads featured a 2.165/1.59 valve combination and peak flow numbers of 317 cfm on the intake and 223 cfm on the exhaust.

What heads came on a LQ4?

The 1999-2000 LQ4 had cast iron cylinder heads. All others had aluminum heads.

What heads on LQ4?

The LQ4 offered a static compression ratio of 9.4:1 thanks to a combination of the 317 heads and dished factory pistons. The 317 heads featured 71-72 cc chambers and intake ports said to be modeled after the LS2/LS6 243 heads.

Are L92 heads Cathedral Port?

The LS7, L92 and LS3 heads feature rectangular intake ports. GM cathedral-style intake ports measure in the range of 3.125 inches high by 1 inch wide. These are easy to identify due to their tall, narrow shape and somewhat radiused top profile.

What heads are better 706 or 243?

The 243 head has 2.0″ intake valves and 1.55 exh. The 706 uses 1.89 and 1.55 respectively. The 243 is an excellent head, but losing compression coupled with a larger intake valve in a tiny bore engine isn’t a good combo in comparison to the 706.

What do stock 243 heads flow?

GM 243 (LS6) and 799 (LS2), 218 cc. The 218-cc LS6/LS2 head is a mild upgrade from the basic performance rebuild, which boosts flow by 32.2 cfm on the intake side and 28.5 cfm on the exhaust side, at . 600-inch lift, despite the more cost conscious machine work.

What are Cathedral Port heads?

Traditionally, cathedral-port heads offer smaller chambers than their rectangular-port cousins. The change in compression ratio can be as much as a full point or more, which can improve power by as much as 3-4 percent (near 25 hp on a 600hp motor).

Are 862 heads better than 706?

The 706Vortec heads are even slightly superior to the commonly found 862 heads. The reason is that the 706 heads are SPM (semi-permanent mold) made, while the 862 heads are sand cast. The SPM method is considered to be a more consistent process, but once you port the 862 head, any difference to the 706 head goes away.

What does it cost to port and polish heads?

$200-300. You may be able to get it cheaper if you work a deal. If you have a mild build you can up to 500hp with stock ported heads but it depends on your combo.

What are rectangular port heads?

Rectangular port heads boast a clear advantage in the flow department and are ideal for high-RPM, big-cubic-inch, and purpose-built drag racing applications. Factory castings are capable of 360 to 400 cfm when ported properly, which can make it difficult to justify an aftermarket casting.

What are 241 heads?

The 241 heads were used on 5.7L LS1 applications and are considered by many to be just a minor step up in performance from the 706. In terms of peak flow, the 241 heads offered 242 cfm at 0.700-inch lift from the 199cc intake ports, and 204 cfm from the 71cc exhaust ports.

What heads come on a LY6?

What really sealed the deal on the LY6 was the use of LS3-style rectangular port heads. The 823 aluminum heads offered peak flow numbers of 317 cfm—a jump of over 65 cfm per runner compared to the 317 heads used on LQ4s and LQ9s. We like to think of the LY6 as a smaller, iron horse version of the all-aluminum LS3.

What is the difference between 821 and 823 heads?

From what I understand there is no real difference in the 821 and 823 other than valves and springs. The Ls3 version has the light weight valves and better springs. There is another casting number for the L92’s that is suppose to be a rougher earlier design, that would be the one to avoid unless it’s ported.