What Is the Difference Between 5.7 Vortec Heads & Regular 350 Heads?

by Allen Gagle
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Engine technology is both a passion and an obsession for car engineers and car aficionados alike. This is due to the fact that the modern internal combustion engine is an imperfect design and could benefit from a few tweaks to squeeze out more power and efficiency from the system.

The Vortec line of cylinder heads was introduced by GM in 1988 as a V6 with a 4.3-liter displacement. This technology created a vortex or pressurized swirl of fuel and air mixture inside the combustion chamber that enables the engine to produce more power while still gaining a marginal amount of fuel efficiency.

Vortec Means Power

Vortec heads instantly added 55 or more horsepower to a regular 350 head with the same displacement. Automotive enthusiasts are quick to note that the 350 and the 5.7 Vortec are essentially the same engine with the same displacement. The 350 designation is the cubic inch measurement that also translates to 5.7 liters.

It is hard to tell the two cylinder heads apart when it comes to the physical aspect of the build, but there are major differences that make Vortec heads more powerful and efficient.

5.7 Vortec Heads and Regular 350 Heads

The intake port of the Vortec head is different and measures 160cc with a modified port that increases the flow velocity. The bowl area is wider around the guide compared with regular 350 heads.

The intake bolt pattern is different and utilizes an eight-bolt attachment. The bolt pattern and the number casting is the quickest way to differentiate a Vortec Head from a regular 350 head. The Vortec head is available in two casting numbers (10239906 and 12558062) that offer identical performance virtues. You can also check the casting mark on the end of the head and check for three triangular saw-tooth casting marks that indicate Vortec potency.

Vortec Intake Valve Seats and Combustion Chamber

The intake valve seat of the Vortec head has a three-angle grind straight from the factory and the combustion chamber design is a radical departure from former GM heads utilized in the market. The Vortec combustion chamber is a kidney-shaped design that promotes better combustion and will have the spark plug located near the center of the chamber.

The regular 350 head utilizes a 90 degree intake bolt angle while the Vortec makes do with a 72 degree bolt angle. Experienced mechanics are all too familiar with the lay out of a Vortex head as all the attachment bolts point straight up when the head is bolted to the engine.


The Vortec head is without a doubt engineered towards producing more power, torque and engine response while improving overall fuel economy. If you plan to change or modify the head of the 350 engine in your car, installing a Vortec head alone will yield positive effects in your quest for power and speed.

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