How to Choose the Right Camshaft for Your LT4
What Nearly 100 Dyno Pulls Taught Us
If you've spent any time shopping for a camshaft for an LT4, you've probably noticed that everybody seems to have an opinion about which cam is “best.” Stage 1. Stage 2. Stage 3. Sleeper cams. Blower cams. Custom cams. More lift. More duration. Wider LSA. Bigger fuel lobe… It can get confusing very quickly.
Before the 2026 LT Engine Camshaft Shootout, I had some strong opinions. But after spending five days on the dyno, making nearly 100 pulls, testing multiple camshafts, two different superchargers, ported cylinder heads, different boost levels, multiple combos and then collecting 5.5 million data points and then spending weeks analyzing the data… my opinions about camshafts and combos have evolved and improved.
But one of my biggest takeaways was actually pretty simple: There is no single “best” LT4 camshaft.
There may be a cam that makes the most peak horsepower in a particular combination. There may be one that makes more average power over a particular RPM range. There may be another that gives you better street manners, requires less RPM, is easier on the valvetrain, or simply sounds better.
The question I get from customers all the time is: “What cam should I put in my car?”
My answer usually starts with another question: What are you actually trying to make the car do?
Because before I care about the name on the camshaft box, I want to know where you want the engine to make power, how high you're willing to spin it, what supercharger you're running, what fuel you're using, what you're eventually going to do to the car, and how much drivability you're willing to give up.
So, this isn't going to be a boring recap of our camshaft shootout. Instead, I want to use some of what we learned during that testing to explain how I personally approach choosing a camshaft for an LT4.
Chapter.1 - There Is No “Best” LT4 Camshaft
When somebody calls Griffin Motorsports and asks me what cam they should buy, I'm generally not going to answer until I know something about the car.
Is it a daily driver? A weekend car? Road-course car? 60–130 car? Drag car? Do you care about having a really choppy idle? Are you running the stock 1.7L supercharger, a ported 1.7L, a 2650, or a 3.0L? Stock heads or ported heads? Pump gas or ethanol? Are you trying to make 750-wheel horsepower or 1,200?
And maybe most importantly: How high do you actually want to spin the engine?
That's because “best” changes depending on what you're asking the engine to do. A camshaft that is extremely happy making power from 4,000–6,300 RPM may be a fantastic street cam. That same cam can still make huge horsepower with a big enough supercharger, but it may not be the cam I'd choose if your entire goal is to accelerate from 60–130 mph as quickly as possible and you want the engine pulling hard through 7,000+ RPM.
Likewise, installing a big high-RPM cam in a mostly stock LT4 that spends 99% of its life cruising around town may give you a great idle and a dyno graph you can brag about, but it might make the car worse at the thing you actually use it for.
That's why my first question isn't: How much horsepower do you want?
It's: Where do you want the engine to be good?
Chapter.2 - Where Do You Want to Make the Power?
This is probably the biggest thing I try to get customers to think about.
Let's say you tell me: “I want to make 1,000 wheel horsepower.”
Okay. Where do you want to make 1,000 horsepower?
Because an LT4 that reaches 1,000 horsepower around 6,200 RPM can be a completely different animal from an LT4 that's still pulling hard at 7,500–7,700 RPM.
Both made 1,000 horsepower. They just got there differently.
A smaller camshaft does not automatically mean the engine can't make big horsepower. There are cars making enormous power with relatively small cams. Give the engine enough blower, enough fuel and enough airflow and you can force a lot of air through it.
But eventually something becomes the restriction. And as airflow demand and RPM increase, the camshaft becomes increasingly important. That's where I think people sometimes get too hung up on a horsepower rating for a cam.
I don't particularly like the question: “How much horsepower will this cam support?”
A better question is: “What does the rest of the combination have to do to make that horsepower with this cam?”
You can make horsepower with displacement. You can make it with RPM. You can make it with airflow. And you can make it by cramming more boost into the engine.
Those aren't necessarily equivalent ways of getting there.
Smaller Cam, Earlier Power
For a daily-driven or primarily street-driven LT4, I'm generally biased toward a smaller cam. Something in the BTR Stage 1/Sleeper-cam type of category can make excellent power while keeping the useful RPM range lower. You don't necessarily need to spin the engine to 7,000+ RPM every time you want everything it has. And if your blower and heads aren't capable of efficiently feeding the engine at high RPM anyway, installing a cam designed primarily to operate there doesn't magically fix the rest of the airflow system.
Bigger Cam, More RPM
Now change the goal. You have good cylinder heads, a KONG X-Port or larger supercharger, adequate fuel, a valvetrain designed for RPM, and you're building a 60–130 or maximum-effort combination. Now I care considerably more about what happens from roughly 4,000 RPM through the shift point. I don't particularly care if the cam isn't optimized for 2,500 RPM because that's not where you're racing the car.
I want the thing to pull. And that's where a cam like the Rick Crawford design we tested starts making a lot more sense.
Chapter.3 - Understanding Cam Specs Without Becoming a Cam Designer
Let me put an important disclaimer here: I am not a camshaft designer. There are people who understand lobe design and valve events at a level far beyond me. What I do have is experience building and driving these cars, talking with customers, working with some very smart engine builders and tuners, and now a pretty substantial amount of controlled dyno data. So rather than pretending we're all going to become cam designers, let's talk about the specifications in terms of what they mean to the person driving the car.
DURATION.
Duration is essentially how long the valve remains open, expressed in crankshaft degrees. Generally, increasing duration gives the engine more time to move air and tends to move the useful powerband higher in RPM. But intake and exhaust duration don't necessarily need to increase equally. That's important on the LT4. One of the most interesting cams in our testing was the Rick Crawford cam at approximately:
22x° intake / 25x° exhaust duration .65x"/.65x" lift 11x° LSA
That's an enormous 30+ degree intake-to-exhaust duration split. Compare that with some other performance cams that may have substantially more intake duration but considerably less exhaust bias. Why? That's one of the questions our shootout made much more interesting.
The LT4 is a positive-displacement-supercharged engine. Getting air into the engine under boost isn't necessarily the only problem. Getting the cylinder emptied efficiently, particularly as RPM and mass airflow climb, matters tremendously as well. Our testing certainly made me pay a lot more attention to the exhaust side of the camshaft than I did before.
VALVE LIFT.
Lift is how far the valve opens (measured in inches). More lift can potentially expose more available cylinder-head flow, but more isn't automatically better. Eventually you're limited by the cylinder head, lobe design, piston-to-valve clearance, spring package and the rest of the valvetrain. And increased lift usually comes with a cost. More aggressive spring requirements and greater valvetrain stress need to be part of the conversation. If I can accomplish someone's goal with a moderate-lift cam and a .660" spring package without needing to spin the engine excessively, I consider that a legitimate advantage.
LSA “LOBE SEPARATION ANGLE”
LSA describes the angular separation between the intake and exhaust lobe centerlines. People often look at LSA as though it tells you exactly what a camshaft will do. It doesn't. LSA influences overlap and the relationship between the intake and exhaust valve events, but you cannot look at a 115, 118 or 120 LSA by itself and predict the entire personality of the cam. We had cams in our test with similar LSA numbers that behaved very differently because the lobes and duration were completely different. That's an important lesson: Cam specifications work together. Don't shop for an LT4 cam by LSA alone.
OVERLAP
Overlap occurs around the transition from the exhaust stroke to the intake stroke when both valves are open at the same time. At higher RPM, some overlap can help scavenging and cylinder exchange. At idle and very low RPM, that same overlap can contribute to unstable combustion and additional reversion, which is the formal way of describing the glorious CAM CHOP.
Which brings us to something people don't always admit: Sometimes You Just Want the Chop
I've had customers choose a larger cam even after I explained that a smaller cam might actually be better for their performance goals. Why? They wanted it to chop. And that's okay. If having a nasty idle is part of what makes you enjoy the car, then sound is part of your build objective. Just understand what you're trading for it. A cam isn't automatically better because it sounds more aggressive.
Chapter.4 - Match the Cam to How You Actually Use the Car
This is where I think cam selection gets much easier. Forget the stage number for a minute, and tell me what you do with the car.
DAILY DRIVER / MOSTLY STREET
If you're primarily driving around town and occasionally making a pull, I generally lean toward a smaller cam. You want good response, reasonable street manners and a powerband you can actually use without constantly spinning the engine. A Sleeper or Stage 1-style cam makes a lot of sense here. You can still make serious horsepower, you're simply prioritizing where and how the engine delivers it.
WEEKEND / SPIRITED STREET CAR
Now we can move the needle a little. A Stage 1 or Stage 2-style cam may be a great compromise depending on the rest of the combination. You get more RPM capability and more top-end potential without necessarily committing to the compromises of a maximum-effort cam. For a lot of customers, this is probably the sweet spot.
ROAD COURSE
Road-course cars require a little more thought. A tight technical circuit and a fast track like Sebring aren't asking the engine to do exactly the same thing. But I wouldn't select the cam based simply on “small track versus big track.” I'd look at where the engine actually lives in the RPM range, which depends heavily on gearing, transmission, tire and driver strategy. If you're constantly accelerating out of slower corners and operating lower in the rev range, broad response becomes extremely valuable. If the combination spends significant time at high speed and high RPM, then carrying power farther toward redline becomes much more important.
60–130 / ROLL RACING
This is where high-RPM cams become particularly interesting to me. A 60–130 pull in a properly geared car may start somewhere around 4,000 RPM and live almost entirely in the upper half of the engine's operating range. I don't necessarily need maximum torque at 2,500 RPM. I need the engine to pull hard through the gear, shift, and keep pulling. And there's another possible benefit: A combination that doesn't deliver one enormous low-RPM torque hit may be easier to hook. For this type of build, I become much more interested in something like the Crawford cam, particularly when it's paired with a ported or larger supercharger and good heads.
Chapter.5 - Build the Combination, Not Just the Camshaft
This might be the most important philosophy behind how we build LT4s at Griffin Motorsports. I don't like making horsepower by simply forcing more and more boost through a restrictive engine. There are better ways.
My hierarchy for making power is generally:
1. Better fuel (E85)
2. More engine efficiency (Heads + Cam)
3. More supercharger efficiency (Porting or 2650 / 3.0L)
4. More boost (Boost is last intentionally)
1. BETTER FUEL
If ethanol is readily available and the fuel system supports it, moving from pump gasoline toward an ethanol blend will be one of the most cost-effective changes you can make. You gain detonation resistance, which will allow the tuner to run the ignition timing the combination actually wants instead of using boost to compensate for limited octane.
2. MAKE THE ENGINE MORE EFFICIENT
This means things like: Cylinder heads. Camshaft. Exhaust flow. Make it easier for the engine to move air. During our build-up testing, the Flag Motorsports Mach V Cylinder Heads produced one of the results that surprised me most. With the cam and additional boost already installed, adding the ported heads took us from approximately 789 hp to 845 hp. Then things got much more interesting. With the KONG X-Port already installed, adding those same heads took us from approximately 906 hp to 1,006 hp. That's 100 horsepower from just ported heads, which actually lowered our boost by approx. 1 psi.
The reverse comparison was equally impressive: with the ported heads already installed, moving from the stock blower to the X-Port was worth approximately 161 horsepower. The parts weren't simply adding fixed horsepower independently.
They were removing restrictions from each other.
That's why, if the engine is already coming apart for a camshaft and the budget allows it, I'm a big believer in doing the cylinder heads at the same time. Trying to recover that airflow later by simply spinning the blower harder is usually not how I'd choose to make the power.
3. USE A MORE EFFICIENT SUPERCHARGER
A better supercharger moves the required mass airflow without needing to create as much heat and pressure to accomplish the job. That could mean shipping your blower to KONG for their famous X-Porting service, or stepping into a 2650 or 3.0L supercharger depending on the goal. Keep in mind, as the blower becomes less restrictive, cam selection becomes increasingly important because the camshaft and cylinder heads become larger parts of the remaining airflow equation.
4. ADD MORE BOOST
Sometimes you simply need more boost, and that's fine, But I want it to be the last lever we pull, not the first. Clearly you can make 800–900 rwhp through a bone stock LT4 by applying 22+ psi (and making a tremendous amount of heat in the process) or… you can make the same 800-900rwhp with 14–15 psi, and a lot less heat.
Chapter.6 - Fuel, Cylinder Pressure and Why Boost Isn't Free
This is an area where it's easy to oversimplify what a dyno is telling you. Boost pressure is not airflow. Boost is manifold pressure (behind the valve) If the supercharger is trying to move air into the engine faster than the engine can process it, manifold pressure rises. Open up the airflow path and boost can actually drop while horsepower increases. Our shootout gave us a dramatic example.
The BTR Stage 0.5 combination made approximately: 951 hp at 18.9 psi.
The Rick Crawford combination made: 1,006 hp at 15.8 psi.
That's approximately 55 additional horsepower with 3.1 psi less measured manifold pressure. That does not mean we measured cylinder pressure and proved the Crawford cam reduced it by some specific amount. We didn't. Manifold pressure and cylinder pressure are not the same measurement. But it tells us very clearly that these combinations were processing airflow differently. Valve timing also affects how much charge becomes trapped in the cylinder and therefore influences dynamic cylinder pressure. Intake closing, exhaust opening, overlap, compression ratio, boost, ignition timing and fuel quality all become part of that equation.
This is why I get nervous when somebody wants to make a lot of power on marginal pump gasoline by simply adding boost. On a supercharged LT4, detonation resistance matters. If E85 allows you to run appropriate timing and make the same power with less boost, I'll take that approach all day over leaning harder on a hot supercharger with inadequate octane.
Ultimately, the customer and tuner determine how aggressively the engine gets pushed. My job is to help build a combination that doesn't require brute force to make the number.
Chapter.7 - Reliability: Don't Use More Cam Than You Need
Here's another thing that gets lost in horsepower discussions: RPM isn't free. Neither is lift. As lift, spring pressure and engine speed increase, demands on the valvetrain increase too. That doesn't mean a big cam is unreliable, It means the valvetrain needs to be appropriate for what you're asking it to do.
If somebody tells me: “I want the most power I can reasonably make, but reliability is extremely important and I don't want to spin this thing to the moon,” I'm not automatically going to put them into the biggest cam available. Something like the BTR Stage 1 V3 we tested is a great example of the philosophy.
It made 981 horsepower in our test combination, with relatively moderate lift compared with the most aggressive cams, and it didn't require us to chase the highest RPM in the test. For the right customer, that's a feature, not a compromise.
M6 vs. Automatic
Most of my firsthand experience is with manual-transmission LT4 cars, so I'm not going to pretend to be an authority on cam selection for an A10. Transmission behavior absolutely matters, however. Gearing, converter characteristics, shift RPM, and where the transmission drops the engine after each shift all affect the RPM range the cam actually needs to support. If you're building an automatic combination, those factors should be considered alongside the normal engine and airflow considerations when selecting the cam. To be safe here, we suggest you consult your tuner to discuss converter changes.
Chapter.8 - What Nearly 100 Dyno Pulls Actually Changed My Mind About
Our camshaft shootout clearly deserves its own article… probably several of them. But there were a few things that genuinely changed the way I think about LT4 cam selection.
1. MORE BOOST DEFINITELY DIDN'T MEAN MORE POWER
This might be my favorite result from the entire test. We had one combination making approximately 951 horsepower at 18.9 psi and another making 1,006 horsepower at only 15.8 psi. That's an enormous difference in how effectively the engine was processing the air the blower was supplying. It reinforced something that has become central to how I approach these cars: I want more airflow, not simply more pressure.
2. THE EXHAUST SIDE DESERVES MORE ATTENTION
Rick Crawford's cam was unusual, and it won the peak horsepower portion of our X-Port testing at: 1,006 hp at approximately 7,000 RPM. What I find particularly interesting is that the Zucker Cam had approx. 10 degrees more intake duration, and didn't beat it. I am not prepared to say that 22x degrees is some magical maximum intake duration for an LT4. Our test doesn't prove that. But it absolutely made me question the assumption that a bigger intake lobe is automatically the path to more power on a positive-displacement-supercharged LT4. Perhaps one of the more important problems at high RPM is getting the cylinder emptied effectively. That's something I want to continue learning more about from the people who actually design these cams.
3. THE BIGGER BLOWER CHANGED THE CONVERSATION AGAIN
We tested the Zucker cam with the KONG X-Port and then kept the camshaft in place and installed the Whipple 3.0L. With the X-Port, the combination made approximately: 1,004 hp at 6,950 RPM. With the Whipple: 1,101 hp at 7,190 RPM.
Roughly 97 additional horsepower, and the engine was still carrying power beyond 7,000 RPM. That's fascinating. Does the Zucker cam's additional intake duration become more valuable once the 3.0L blower can supply substantially more airflow? Maybe. Would the Crawford cam have made even more power with the Whipple because of its enormous exhaust duration? Maybe.
Unfortunately, we didn't run that A/B test. And I'm not going to invent an answer because I wish we'd tested it. What the result does show is that the ideal camshaft can change as you move the restriction somewhere else in the system.
4. OUR TORQUE DATA HAS AN IMPORTANT LIMITATION
This is worth being completely transparent about. Our shootout was not designed to determine which camshaft makes the best 2,500–4,000 RPM street torque.
We intentionally loaded the dyno after that region and softened timing around peak torque because we were primarily interested in repeatable high-RPM horsepower testing and protecting the engine throughout an enormous number of pulls. So, when you see the torque numbers from our shootout, understand what you're looking at. There is useful information in the upper part of those curves.
But I'm not going to look at those graphs and tell you Cam A is definitively the better low-RPM street cam than Cam B. We didn't test that question properly, and I think saying that is important.
Good testing isn't just knowing what your data proves, It's knowing what it doesn't prove.
Conclusion - Which LT4 Cam Is Best for Your Build?
If you called me today and asked: “Gabe, what's the best cam for my LT4?”
I'm probably going to ask you a bunch of questions before I give you an answer. What power are you trying to make? Where do you want to make that power? How high are you willing to spin the engine? What fuel are you running? What blower do you have? What cylinder heads? What transmission? What are you eventually going to do to the car? How important is street drivability? How important is reliability? And yes: How important is the chop?
If it's primarily a street car and you want strong power without living at 7,000 RPM, I'm probably going to steer you toward the smaller end of the spectrum.
If you want something that gives you more room to grow while maintaining reasonable street manners, a middle-ground Stage 1/Stage 2-style combination may make more sense.
If you've got good heads, a ported or larger blower, adequate fuel, the right valvetrain, and your goal is maximum-effort high-RPM power, then something like the Rick Crawford cam becomes extremely compelling.
And if you tell me you're doing an X-Port today but there's a 2650 or 3.0L in the car's future? I'm going to think very carefully before putting a small cam in the engine just because it works well with today's combination. You don't necessarily need to buy the camshaft twice. But you also shouldn't sacrifice the way you actually use the car today for some theoretical modification you may never install.
That's ultimately the point. Don't choose your LT4 cam by asking which one makes the biggest number. Choose the cam that makes the kind of power you actually want, in the RPM range where you intend to use it, with the rest of the combination built to support it.
That's the difference between installing a camshaft and building an engine combination.