Are 317 Heads On 5.3 Good? The Ultimate Answer

Many car owners think of putting 317 heads on 5.3 as this small, simple engine component can greatly influence the car’s performance and fuel consumption.

So, what exactly is this detail, and is it possible to do so? Let’s learn more about its specs and its counterparts in the sections below!

Are 317 Heads On 5.3 Good?

317 heads on 5.3

Though the debate of 317 vs. 706 heads seems to never end, I can’t deny that 317s are good for turbocharged engines.

If the 706, 243, or the later 799 is the go-to head for any engine, the 317 is just right behind.

It’s designed with the same ports as the 799 and 243 types but with larger chambers.

What Are Engine Heads?

These engine components, also known as cylinder heads, are filtration devices located on top of the engine.

Their duty is to regulate the gas inflow and outflow through the combustion chamber and control the fuel deployment.

Many people think that engine combustion only includes burning fuel, yet it’s more complicated than that.

The process of burning should be done evenly. If not, it will affect the engine’s efficiency.

That’s why you need the proper details and they’re more important than people think.

Besides, paying attention to the cylinder heads is not enough, you should take care of the cylinder wall damage as well.

The component is in charge of keeping an efficient combination of oxygen and fuel in the combustion chamber all the time.

The 20-70 brake horsepower is what distinguishes the good and bad details. Plus, when you use a bad one, the fuel efficiency will decrease by 50%.

What Are The 317 Specs?

Valve SizeIntake2.00
Port VolumeIntake212 cc
Exhaust76 cc
Combustion Chamber71.5 cc
Target Bore Size4.000
Chamber Diameter3.923

317s are said to have a similar intake port design to the 799 or 243 types.

According to LS 317 head specs and after my testing, I consider it an excellent option. They provide greater volumes of airflow (compared to the 243, for example).

Compared to the 706 models, 317s create more flow (maximum 20 CFM at some lift points.)

The 71cc combustion chambers allow them to defeat their competitors. It’s 15% more than the 706 and 20% more than the 243. 371’s compression level ranges from 8.3:1 to 9.5:1.

Machine the components to increase airflow so that you can adjust their suitable compression range. The chamber diameter of 317s is 3.923 inches and can fit engine sizes of up to 6 liters.

What Can Compare With 317?

ls 317 head specs

241 Heads

The component was applied on 5.7L LS1. Many people think it made only small progress compared to the 706s. Here are the specs of 241.

Valve SizeIntake2.00
Port VolumeIntake199 cc
Exhaust71 cc
Combustion Chamber68 cc
Target Bore Size3.898
Chamber Diameter3.821

799 Heads

The 799 type has the smallest combustion chamber (64cc) with a 3.876-inch chamber diameter. Let’s look at the table below for more details of this component!

Valve SizeIntake2.00
Port VolumeIntake209 cc
Exhaust74 cc
Combustion Chamber64 cc
Target Bore Size4.000 (and 3.780)
Chamber Diameter3.876

706 Heads 

Here are the 706 LS head specs.

Valve SizeIntake1.89
Port VolumeIntake197 cc
Exhaust69 cc
Combustion Chamber61.5 cc
Target Bore Size3.780
Chamber Diameter3.756

Are 706 heads good? It’s always been legendary among car lovers. However, other types are not far from behind. Let’s quickly compare these components!

706 Vs. 317 Heads

As mentioned above, 317 truck heads are improved with the same port as the 799 and 243, but the 317 offers a larger combustion chamber.

It’s considered a positive feature for turbo and (blower) engines.

In reality, the Dyno tuning or Dyno testing of 5.3 with 706 heads hp shows that the ported 706 heads hp gain or improve its power output by 20 hp and 15 lb-ft over the 317 ones, though the latter has larger valves than the former.

However, if you don’t mind the milling cost, you can do it with the 317 types and have it perform better on 5.3L.

You can also pay for the cost to dyno your car to understand more about your car status before installing new details.

706 Vs. 241 Heads

Regarding combustion chambers, the 241 type provides larger cc than the 706 (68cc vs. 61.5cc). It means there’s a drop in compression of about 0.70 when proceeding with the head swap.

706 Vs. 799 Heads

When testing these two types: 799 vs. 706 heads on the 5.3L engine, I discovered that the 799 made the most flow, but it couldn’t translate into power. In this case, the 706 did a better job.

706 Vs. 862 Heads

The 706 model is made to be superior to the common 862. The semi-permanent mold (SPM) method is a consistent process.

Though the 862 can nullify the difference between them, I still vote for the 706 due to the porting costs of cash.


706 vs 317 heads

Is The 317 Model Good For Turbocharging?

Yes, the compression ratio allows them to be suitable for turbocharging. Usually, you need to reduce the engine compression levels to do the process.

It’s a huge decrease that can make the whine work less efficiently.

However, the 317 heads 6.0 have the right compression ratio for turbo application, allowing you to make full use of the details.

How Much Do 317s Cost?

The full set costs around $450 – $600 depending on the condition and how you want out of the detail.

You can order a new, machined-down one and have a professional swap out all the old ones with a total price of about $1100.

The Bottom Lines

It’s not surprising when you see 317 heads on 5.3, as it has the right size to fit most engines.

The components are an excellent aftermarket upgrade that can benefit your vehicle with high performance (you may have an extra 50 horsepower), fuel economy, and affordable price.

That explains why the detail is so popular in the car world.

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