I previously published an article about the 5 best 6.4 HEMI engine upgrades. Intake manifolds didn’t quite make the primary list, but we did briefly discuss manifolds as an honorable mention. Now, it’s time to expand on intake manifold upgrades and discuss this mod in greater depth. In this article, I look at 6.4 HEMI manifold upgrades & porting, costs, benefits, hp gains, and discuss some of the best upgrades.
*This article discusses intake manifold upgrades and porting for the 6.4L HEMI specifically. If you’re looking for info on 5.7 HEMI manifold upgrades (or swapping a 6.4 manifold onto the 5.7) then check out our 5.7 HEMI intake manifold article.
6.4 HEMI Stock Intake Manifold
Before diving into porting and upgrades it’s important to discuss the stock intake manifold on the 6.4L V8. The quick note in the intro is there for good reason. A lot of people look to the 6.4 HEMI intake to swap onto their 5.7L HEMI engines, and it’s an excellent upgrade.
The 392 HEMI intake manifold uses an active runner design. Up to 4800rpm the 6.4 HEMI intake operates in long-runner mode for better torque on the low-end and mid-range. Above that RPM it then switches to short-runner to maximize top-end horsepower.
Point is – the stock manifold is a great design. It’s one of the primary reasons intake manifolds didn’t quite make our list of the top 392 HEMI mods. There are likely better upgrades to spend the money on. However, intake manifold upgrades or porting of the stock manifold does make sense for some. If you’re looking for a maximum power N/A build then an intake manifold is certainly a great addition.
392 HEMI Manifold Upgrade Benefits
Benefits of an intake manifold upgrade or porting include:
- 5-10whp (more possible)
- Similar torque gains
- Stronger manifold
- Louder engine note
- Cleaner engine bay
Some of the benefits of 392 HEMI manifolds depend on whether you opt for porting or an actual aftermarket option. We’ll discuss this in more depth in the next section and also when we discuss some of the best 6.4L V8 manifold upgrades.
Anyway, horsepower gains will likely fall in the 5-10whp. You may pick up a bit more or less power depending on other mods on the 6.4 HEMI. As a side note – combining a ported intake manifold and 88mm throttle body is a good choice. Some dynos have shown gains in the 15-20whp with the combination. Torque gains generally fall in the same ballpark.
The remaining benefits are mostly for those looking to go with an upgraded 6.4 HEMI intake manifold. Stock 392 manifolds are made from plastic whereas upgrades are generally aluminum. With this change you’ll get a stronger manifold, slightly louder engine note, and a possibly a nicer looking engine bay.
Intake Manifold Porting vs Upgrades
As discussed, the design of the 392 HEMI manifold is great from the factory. Active runners really do a great job of maximizing performance across the whole power band. For N/A 6.4L V8 engines we believe sticking with OEM manifold and simply porting it is the best option. Most agree the price of an upgraded manifold simply isn’t worth it.
Then, why do aftermarket 6.4 intake manifolds even exist? True upgrades can be a great option depending on your specific build. If you’re adding boost (especially for the high boost & power builds) then an aluminum manifold goes a long way. Having a bit more strength than the OEM plastic manifold certainly won’t hurt.
There are also some awesome looking upgrades that give a great look and sound. Otherwise, 6.4 HEMI intake manifold upgrades can still offer good performance. They’re generally designed for top-end power, though. It might make sense for certain builds, but if you want street performance then the mid-range of the OEM manifold is ideal.
Best 392 HEMI Intake Manifold Upgrades
With the background info and benefits out of the way let’s dive into the best 6.4 HEMI intake manifold mods. Please note – this is far from an exhaustive list and plenty of great options exist. We simply can’t cover every option in one article. Instead, the options below are some of the intake manifolds we believe offer the best balance of price, quality, and performance.
Ensure you understand your goals and needs before upgrading your 6.4 HEMI intake manifold. Remember, some may be designed more for top-end power rather than a balanced powerband for street use. We’ll specify where applicable. Anyway, time to jump in and discuss some of the best 392 HEMI manifolds.
1) Intake Manifold Porting
Buy Here: 392 HEMI Manifold Porting
Porting the stock HEMI manifold is likely the best route for most 392 owners. Again, the active runner design is great for maximizing output throughout the whole powerband. Porting the intake keeps the same active runner design and simply helps move more air thru the manifold.
On a bone stock 6.4 HEMI the gains from porting the intake manifold are minimal. The OEM design is plenty efficient at stock output. However, once you begin adding power from other mods like tuning, headers, cams, etc. then the additional airflow from porting is beneficial. Expect gains in the 5-10whp ballpark and possibly 15-20whp when combined with a throttle body upgrade.
The 392 HEMI manifold costs about $300-400 for porting. You may have to send your manifold in advance at some stores or shops. Others may have core charges that are refunded once you send your stock manifold back. Another option is choosing a brand new manifold but that can add $400-500 onto the price.
Anyway, the relatively low price of porting the intake manifold makes it a worthwhile upgrade. That’s especially true if you’re looking for a max effort NA 6.4 HEMI build.
2) Holley Sniper EFI Intake
Buy Here: 6.4 HEMI Holley Intake Manifold Upgrade
With porting out of the way it’s time to move onto true aftermarket 6.4 HEMI intake manifolds. This is the manifold pictured at the start of the article and it looks absolutely killer. The hi-ram manifold is fully TIG welded and uses 1/8″ truck aluminum. It’s sure to add some strength for those looking to go with boost.
The Holley manifold does include gaskets, high-flow fuel rails, and all the hardware required. This EFI version has 92mm or 102mm throttle body openings to bring out the full potential in throttle body mods. Ultimately, this is a great choice at less than $700.
This manifold is designed for top-end power, though. Some people may prefer that even for street driving. However, most street driving occurs in the lower and mid-range where the 6.4 HEMI ported intake manifold excels. Regardless, the Holley Sniper EFI manifold is certainly a tempting option with plenty of benefits.
3) Edelbrock EFI Intake Manifold
Price: $1,079.95 (+223.95 required fuel rail kit)
Buy Here: Edelbrock Victor EFI HEMI Manifold
The Victor EFI manifold from Edelbrock is another great option if you’re looking for an aftermarket upgrade. Design of the intake is similar to that of the 6.1L SRT intake manifold. However, it uses longer, higher flowing runners along with relocated injector bosses and additional bosses that can be used for nitrous.
Edelbrock claims the Victor EFI prototype was good for 25 horsepower over a stock 6.4 HEMI intake manifold. We believe those numbers are a bit aggressive, and most won’t see that big of a hp gain. Regardless, it’s a well designed intake manifold that certainly has some potential.
One primary downside to the Edelbrock option is price. The manifold requires adding a fuel rail kit for an extra $223.95. That brings the total cost just over $1,300 which is tough to swallow.
Nonetheless, Edelbrock is a well known brand that builds quality products, so it’s fair to say you’re paying a premium for that. Porting the 6.4 HEMI intake manifold or the Holley Sniper would be our first picks. The Edelbrock manifold is still a great option if spending the extra money isn’t a big concern.
6.4L HEMI Manifold Upgrade Summary
The 6.4 HEMI is a stout engine that responds well to upgrades. An intake manifold is a great mod for those looking to maximize power on a NA setup (or for those needing a stronger manifold to tolerate boost). However, it didn’t quite make our list of the 5 best upgrades for the 392 HEMI.
Starting with bigger power mods like cams, headers, cold air intake, and tuning is likely the best bet. That doesn’t mean an intake manifold can’t be a good upgrade, though. Porting the stock 6.4 HEMI intake manifold can show gains of 5-10+whp; not bad for roughly $300-400.
Those looking for a true aftermarket upgrade will end up spending a bit more. However, upgraded manifolds can offer improvements in strength, engine sounds, and looks. The right intake manifold can also offer solid power gains, but some may trade off a little mid-range in favor of top-end power. Holley Sniper EFI and Edelbrock EFI manifolds are both excellent options for the 392 HEMI.
What’s your experience with 392 HEMI manifolds? Are you considering one?
Leave a comment and let us know!