If you're hunting for the anderson b31 cam specs, you probably already know that this particular camshaft has a massive reputation in the Ford pushrod community. For decades, the 5.0L Mustang crowd has looked to Anderson Ford Motorsport for the secret sauce to make their cars move, and the B31 is often the go-to choice for guys running a centrifugal blower. It's one of those parts that just seems to work, even if the design has been around for a while.
When you start digging into the technical side of the anderson b31 cam specs, you'll see why it's so popular. It isn't just a random set of numbers; it's a profile designed to maximize the air coming from a Vortech or a ProCharger while keeping the car streetable. Let's break down what actually makes this cam tick and why it might (or might not) be the right fit for your engine build.
The Raw Numbers: What You're Getting
The heart of any cam discussion is the spec sheet. For the B31, the numbers are pretty specific. We're looking at a hydraulic roller camshaft designed primarily for the 1985–1995 Ford 302 engines.
The duration at .050" lift is 218 degrees on the intake and 228 degrees on the exhaust. That 10-degree split is a huge hint at its purpose. In the world of forced induction, you really want that extra exhaust duration to help blow out the spent gases that the supercharger is shoving in. Without that split, you can end up with a lot of backpressure that kills your top-end power.
Then you have the lift. With a standard 1.6 ratio rocker arm, the B31 provides .544" of lift on both the intake and exhaust sides. This is a solid amount of lift for a street car. It's enough to get the valves open wide and let the heads breathe, but it's not so aggressive that you're constantly snapping valve springs or worrying about clearance every time you hit the rev limiter.
Lobe Separation and Power Band
Another crucial part of the anderson b31 cam specs is the Lobe Separation Angle (LSA). The B31 sits at 112 degrees. This is a bit of a "sweet spot" for many tuners. A 112 LSA gives the engine a distinct, choppy idle—that classic Mustang "lope"—without making it a nightmare to drive in traffic. It also helps build a broad power curve.
The RPM range for this cam is usually rated from about 2500 to 6500 RPM. That's exactly where you want a street/strip car to live. It's got enough bottom-end grunt to get you away from a stoplight without stalling, but it really starts to scream once the blower builds boost around 3000 RPM.
Will It Clear My Pistons?
This is the question that keeps Mustang owners up at night. One of the biggest selling points often mentioned alongside anderson b31 cam specs is that it's often touted as a "bolt-in" cam for stock pistons. Because the intake duration is relatively modest at 218 degrees, the valve usually isn't open deep enough into the cylinder to smack the piston on a standard 302 bottom end.
However—and this is a big "however"—you can never take that for granted. If you've milled your heads, if you're using thinner head gaskets, or if you've switched to aftermarket heads with larger valves, you must check your piston-to-valve clearance. I've seen guys throw these in and have plenty of room, and I've seen others who were uncomfortably close because of a slight variation in their build. It's always better to use some modeling clay and rotate the engine by hand than to find out the hard way at 6000 RPM.
The Sound and the Street Manners
Let's be honest, half the reason we buy cams is for the sound. If you're looking at the anderson b31 cam specs and wondering if it'll give you that "thump," the answer is a resounding yes. It's not so aggressive that the car shakes itself apart, but everyone at the gas station will know you've got something under the hood.
In terms of driving, the B31 is surprisingly polite. With a decent tune, it'll lug around in fifth gear at 45 mph without bucking or surging. That's the beauty of the 112 LSA. It keeps enough vacuum for your power brakes to work properly, which is something people often forget about until they're trying to stop a 3,300-pound car with a pedal that feels like a brick.
Best Supporting Mods for the B31
You can't just throw a cam in and expect magic if the rest of your parts aren't up to the task. To really make use of the anderson b31 cam specs, you need a top end that can flow.
- Cylinder Heads: While you can run this on stock E7 heads, it's a bit like putting a marathon runner's lungs into a chain smoker. Aftermarket aluminum heads (like AFR 165s or 185s, or Trick Flow Twisted Wedge) are where this cam really shines.
- Intake Manifold: A stock Ford intake is going to choke this cam out by 5000 RPM. You'll want something like a Holley Systemax or an Edelbrock Victor Junior to keep the air moving.
- Valve Springs: Don't even think about using stock 30-year-old springs. The .544 lift will turn them into wet noodles in about five minutes. You need a spring rated for at least .600 lift to ensure you don't experience valve float at high RPM.
- Gears: Since the power starts at 2500 RPM, a set of 3.55 or 3.73 gears in the rear end will help you get into the meat of the power band much faster.
Why Choose the B31 Over the B41?
If you're browsing Anderson's catalog, you'll see the B41 right next to the B31. The B41 is the bigger brother, with more lift and duration. So, why stick with the B31?
It really comes down to your goals. The B31 is the "safe" bet for a car that sees a lot of street miles. It's easier on the valvetrain, more likely to clear stock pistons, and has slightly better low-end torque. If you have a dedicated track car or a 347 stroker, the B41 might be the better choice, but for a standard 302 with a Vortech S-Trim, the B31 is arguably the most balanced option out there.
Tuning Is Not Optional
Back in the day, guys used to "FMU" their way through blower builds, but we know better now. If you're installing a cam with the anderson b31 cam specs, you really need a proper tune. Whether you're using a Moates Quarterhorse, a Megasquirt, or a modern Holley EFI system, getting the fueling and timing right is what makes the difference between a car that makes 350 horsepower and one that makes 450 horsepower.
Because of the increased lift and duration, your mass air meter needs to be calibrated correctly, and your idle air control settings will need a little massage to keep the car from stalling when you dip the clutch coming to a stop.
Final Thoughts on the B31
The anderson b31 cam specs represent a golden era of Ford performance. It's a tried-and-true profile that hasn't changed much because it simply doesn't need to. It offers a great mix of "show" with its lopey idle and "go" with its blower-friendly timing events.
Is it the most modern, computer-optimized profile on the market today? Maybe not. There are custom grinders who can tailor a cam specifically to your exact cylinder head flow and exhaust backpressure. But for the average enthusiast who wants a proven performer that sounds mean and makes great power under boost, the B31 is a classic for a reason. It's a "set it and forget it" kind of part that has put thousands of Mustangs into the 11s and 10s at the drag strip while still being able to drive to the local car show on Saturday morning.
Just remember: check your clearances, upgrade your springs, and get a good tune. If you do those three things, the B31 will probably be the best mod you ever do to your small-block Ford.