Are Chevy 434 heads any good?

Chevy 434 Heads: An Overview
The Chevy 434 heads have received mixed feedback over the years. Here’s a summary of the information available:
Feedback from Enthusiasts
– Some enthusiasts have expressed that the 434 heads are just basic large chamber smogger heads from the 70s, with nothing exceptional about them. They can be ported into the 250cfm intake range, but the chamber shape is not the best for good power. Other heads, such as the “fuelie” 64cc chamber or the modern fastburn and heart-shaped chambered heads, are reported to return more torque and horsepower when ported exactly the same way due to their better chamber shape.
– On the other hand, there are reports of individuals achieving good results with the 434 heads, running them on a 327 for about 5 years with pretty good results. However, it’s also noted that they don’t flow that well, indicating a mixed experience with these heads.
Performance and Usage
– The 434 heads are described as large chamber smogger heads from the 70s, and their performance may not match modern alternatives, such as the AFR 227 heads, which are considered to be a good option for the 434 engine.
– It’s mentioned that the 434 heads are heavier and stronger than most 305 heads and are not prone to cracking like most 305 heads. However, there are reservations about their port quality, with some suggesting that it might be better to save money for better heads.
Considerations for Engine Builds
– When considering the 434 heads for a 434ci engine build, it’s important to assess the headflow requirements. Some sources suggest that for a good street engine, increasing the original headflow by 15-20% may be necessary.
– There are also discussions about the reliability of a 434 build, with recommendations to use a 2-bolt block with splayed main caps and to ensure proper component quality for the build.
In conclusion, the feedback on the Chevy 434 heads is varied. While some have achieved decent results with these heads, there are also reservations about their performance compared to modern alternatives. When considering these heads for an engine build, it’s important to carefully assess their suitability and performance characteristics in relation to the specific requirements of the build.

What degree are stock Chevy heads?

23 degrees
A small-block Chevy, for example, employs a factory valve angle of 23 degrees but aftermarket heads are not limited to this angle. Dart offers different valve angles with 18-, 16-, 15-, and even 9-degree heads intended for pure competition engines.

What heads should I put on my 350?

About the only factory 350 heads you should consider are the 062 or 906 “Vortec” heads from ’96-’99 trucks. They require a specific intake manifold, but they are readily available. Putting LT1 heads on a Gen I block is an exercise in how stupid you can be.

How much HP is a 434?

Our 434 Sportsman Engine May Be A Small Block, But At 434 Cubic Inches And 710 Horsepower There Is Nothing “Small” About It!

What is so special about Vortec heads?

The most important detail is that the Vortec uses an eight-bolt intake-manifold pattern that is different from the standard 12-bolt pattern. The Vortec requires a specific Vortec intake manifold available from both GM Performance Parts and Edelbrock.

What SBC makes the most horsepower?

LT5 Gen IV 6.2-Liter Small-Block
The LT5 of 2019 stands as the most powerful production internal-combustion engine ever, at 755-horsepower (and 715-lb-ft of torque!), currently a record for a mass-produced Chevrolet production car.

What is the stroke of a 434 small block Chevy?

It is built around a Dart SHP block with 350 mains, a 4.155-inch bore, 4-inch stroke and standard small block cam location.

What is the bore and stroke of a 434 LS?

It uses a Dart SHP LS Next block, with a 4.155-inch bore and four-inch stroke to arrive at a capacity of 434 cubic inches.

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 much HP can a 434 SBC make?

“Every time we dyno a motor, those spacers seem to be worth 12-18 horsepower every single time,” Brandon says. “The 434 made 636 horsepower with a compression ratio of 13:1.” However, Brandon says the engine could make 650 hp or more under the right circumstances.

What Gen of 350 is the best?

What Year is the Best Chevy 350 Engine?

• LT-1 – 1970. When the LT-1 hit the scene in 1970, it took the world by storm.
• L98 – 1992. Another fan favorite is the 1992 L98 350 engine.
• L31 – 2002. Last but not least, the 2002 L31 350 Crate Motor deserves recognition.