What size are the heads on a big block Chevy?

Big Block Chevy Cylinder Head Sizes
The size of the heads on a big block Chevy can vary depending on the specific model and application. Here are some key points to consider:
– Big block Chevy heads were designed with different combustion chambers, valve sizes, and port dimensions to accommodate various applications.
– The open chamber heads have a larger combustion chamber compared to the closed chamber design, which helps increase airflow at higher RPM.
– Aftermarket manufacturers like Brodix and Carl Foltz Engineering (CFE) offer a range of big block Chevy heads with different features and options.
– The high-performance rectangular port and factory aluminum heads are harder to find compared to the large oval port types.
– Chevrolet Performance offers service replacement cylinder heads for big block Chevy engines, which meet GM’s quality standards and provide excellent service and durability.
– The big block Chevy heads are known for their canted valve design, which allows for a large amount of airflow and contributes to their power capability.
It’s important to note that the specific size of the heads, such as the valve sizes or port dimensions, can vary depending on the specific casting and model. If you’re looking for a specific size or type of head, it’s recommended to consult casting numbers and specifications or consult with a knowledgeable professional.
I hope this information helps! Let me know if you have any other questions.

Are all big-block Chevy heads the same?

All production big-block heads have similar characteristics, including 7/16-inch rocker studs (except Gen V and Gen VI) and the same seven-bolt valve cover pattern.

How much horsepower does a 454 big-block have stock?

The 454 EFI version was rated from 230 hp (172 kW) to 255 hp (190 kW) and from 385 lb⋅ft (522 N⋅m) to 405 lb⋅ft (549 N⋅m) of torque. The 1991–1993 454SS made 255 horsepower at 4000 rpm and 405 lb-ft of torque at 2400 rpm thanks to dual 2.5″ catalytic converters.

What degree are big-block Chevy heads?

We also moved the exhaust valve up against the cylinder bore, but in the opposite direction. A factory big-block Chevy head has 26-degree intake valves canted 4 degrees, and 17-degree exhaust valves canted 4 degrees.

How do you identify BBC heads?

Big-block cylinder heads cast by GM are most commonly identified by their casting numbers, which may be found in a variety of locations depending upon the particular head. However, the complete casting number is located beneath the valve cover, usually above an intake port.

What are good heads for a 454?

The 049’s and the 781’s are the best of the oval port heads. These are open chamber heads and have big combustion chambers and you need a dome piston to get compression out of them. Either one will do as they are almost identical.

What is the difference between a 427 and a 366?

The 427 and 366 have the same bolt patterns for exhaust. The 366 and 427 use the same stroke, but the 427 has a much larger bore. The 366 is a tall deck truck engine and as such will use a different intake manifold.

How do you identify engine heads?

Cylinder heads may be identified by their casting number, located between the #4 and #5 pushrods. General identification is as follows: 850-1100 heads have a heater tap at 90 degrees to the centerline of the engine. The space between the thermostat housing and the valve cover is small, at 1/16″

Is a 327 a big block?

The Chevrolet 327-cubic-inch V8 originated with the small-block family of engines that first appeared in 1955 with a 265 cubic inch powerplant. Following with a 283 cubic inch version that appeared in 1957, the mighty 327-inch small block made its debut in 1962.

What is the difference between 305 and 350 heads?

The 305 heads use smaller valves to clear the 305’s smaller bore. If you use the 350 heads on the 305, you will need to get the bores clearanced so that the larger valves on the 350 heads do not interfere with the 305 block.

How much HP can a 454 big-block handle?

In general, a properly tuned production automotive engine produces 1.0-1.5 hp per cubic inch. Where a particular engine falls depends on many factors, so we’ll use 1.3 hp per cubic inch as a middle figure. That means a 454 can support almost 600 hp (454 x 1.3 = 590.2).