When I set out to build a 400-horsepower small-block Chevy for my 1970 Camaro, I knew the ignition system would be a make-or-break component. After spending countless hours on forums, talking to engine builders, and reading spec sheets, I landed on the MSD Ignition System. Specifically, I chose the MSD 6AL-2 Programmable Digital Ignition Control paired with an MSD Pro-Billet distributor and MSD Blaster HVC II coil. This combination promised not just raw spark energy but precise control over timing curves and rpm limits. Here’s the full story of how that decision transformed my build from a decent street motor into a fire-breathing, razor-sharp powerplant.

Why the MSD Ignition System Was the Right Choice for My 400 HP Build

Let’s start with the why. Building a high-performance engine isn’t just about bolting on bigger heads or a hotter cam. The ignition system must deliver enough voltage and duration to ignite the air-fuel mixture under compression, especially when you’re pushing cylinder pressures north of 180 psi. Stock ignition systems, even performance aftermarket units from other brands, often fall short once you cross the 350-400 HP threshold. MSD has been the gold standard in racing for decades, and their technology trickles down to every product they sell.

Here’s what sold me on MSD:

  • Multiple Spark Discharge (MSD): The system fires multiple sparks at lower RPMs—up to 20 sparks per cylinder at idle—ensuring complete combustion. At higher RPMs, it switches to a single, high-energy spark. This helps with both idle quality and top-end power.
  • Programmable Timing Control: The 6AL-2 allowed me to adjust the initial timing, total timing, and even build a custom timing curve with a laptop. No more swapping springs and bushings in a mechanical distributor.
  • Built-in Rev Limiter: A programmable soft-touch rev limiter that lets me set both a hard limit and a “rev limit for burnout/launch” mode. Ideal for bracket racing or aggressive street driving.
  • Rugged Construction: The control box is resistant to vibration, moisture, and heat. I’ve had mine mounted on the inner fender for two years with zero issues.
  • Proven Reliability: I talked to a local engine builder who swears by MSD for endurance applications—road racing, desert off-road, you name it.

For more technical background, Hot Rod’s MSD ignition 101 article covers the basics of capacitive discharge ignition versus traditional inductive ignitions, which helped me understand why MSD is superior for performance builds.

Installation Process: What I Learned Along the Way

I’ve installed several ignition systems over the years, but the MSD setup was the most straightforward while also being the most thoroughly documented. MSD’s instructions are a model of clarity—complete with wiring diagrams, torque specs, and troubleshooting steps. That said, I’ll share a few tips that aren’t in the manual.

Prepping the Engine Bay

Before touching a wrench, I removed the battery ground cable. Then I pulled the old points-style distributor (yes, I had been using a vintage setup), the old coil, and the ballast resistor. For anyone upgrading from a points igniton, note that MSD systems require a full 12-volt supply—the factory resistor wire must be bypassed. I ran a dedicated 10-gauge wire from the battery positive terminal to the MSD box and installed a 40-amp fuse inline.

Mounting the Control Box

MSD recommends mounting the box away from heat sources and the engine block itself. I chose the passenger-side inner fender, drilling two mounting holes and using the supplied rubber vibration isolators. Make sure the box is grounded with a short, heavy-gauge wire directly to the engine block or chassis—ground loops in MSD installations can cause misfires.

Distributor Installation

The MSD Pro-Billet distributor came pre-assembled with a mechanical advance mechanism. I set the initial timing to 12 degrees using a timing light, then locked the advance curve using the instructions for the 6AL-2. This allowed the ECU to control all timing adjustments via a laptop. I used MSD’s Power Pro Software (free download) to build a 3D timing table based on rpm and throttle position.

Wiring Tips

  • Use MSD’s tach adapter if your tach is old: Some older tachometers don’t like the capacitive discharge signal. MSD sells a simple adapter PN 8920 that fixed my erratic tach reading.
  • Route spark plug wires away from sensor wires: MSD generates a high-frequency spark noise. Keep the wire harness for the crank trigger (if you use one) and MAP sensor clear of the plug wires to avoid misfires.
  • Double-check the coil polarity: The MSD Blaster HVC II coil has a + and – terminal. Reversing them will cause a weak spark and potential misfire at high rpm.

Once everything was wired and the battery reconnected, I cranked the engine. It fired on the second revolution. I let it idle for about 10 minutes to verify timing and check for any wiring issues. The initial idle was already smoother than before.

Performance Improvements: Before and After Dyno Results

I didn’t just guess at the gains. I dyno-tuned the engine before and after the MSD swap on a SuperFlow chassis dyno (DynaPro). The baseline was with a traditional HEI ignition system. The engine made 378 hp at 6,200 rpm and 398 lb-ft at 4,400 rpm. After installing the MSD system and optimizing the timing curve, the same engine pulled 402 hp at 6,400 rpm and 421 lb-ft at 4,600 rpm—a gain of 24 hp and 23 lb-ft. That’s a 6% increase in peak power, but more importantly, the area under the curve was significantly larger. At 3,500 rpm, we saw a 15 hp gain. That translates to better throttle response and a wider powerband.

But raw dyno numbers only tell part of the story. On the street, the MSD system transformed the car’s behavior in these key areas:

  • Quicker Starts: The engine fires almost instantly, even after sitting for weeks. The multiple-spark discharge gives a far more reliable light-off than any inductive system I’ve used.
  • Smoother Idle: With the programmable idle timing (I set 18 degrees at 900 rpm), the engine idles at 850 rpm with a steady vacuum of 15 inches Hg. Previously, I was fighting a lumpy 700 rpm idle that surged on cold mornings.
  • Enhanced Throttle Response: Stabbing the throttle from idle produces an immediate snap. That’s the capacitive discharge delivering full voltage instantly, even at low battery voltage.
  • Increased Power Output at High RPM: Above 5,500 rpm, the MSD system prevents the misfires I occasionally experienced with the HEI. The single high-energy spark sustained clean combustion all the way to my 7,200 rpm rev limiter.

For a detailed analysis of how MSD compares to other high-performance ignition systems, Chevy Hardcore’s MSD vs HEI shootout is worth reading. Their data aligns with what I experienced.

Real Owner Feedback: More Voices from the Garage

I reached out to a few other enthusiasts who have run MSD ignitions in their builds. Their experiences underscore the versatility of these systems.

  • John D. (1970 Mustang, 427 FE): “I switched to the MSD 6AL-2 after fighting a misfire at 6,000 rpm. The MSD fixed it instantly. I also love the two-step rev limiter—I can launch at 3,500 rpm every time.”
  • Sarah L. (1998 Camaro Z28, LS1 swap with 150-shot nitrous): “I was nervous about going from LS direct ignition to an aftermarket setup, but the MSD Atomic EFI with ignition control made installation plug-and-play. My nitrous tune is now safe with the timing retard feature.”
  • Mike R. (1986 Buick Regal T-Type, intercooled turbo 3.8L): “MSD’s programmable boost timing control is a lifesaver. I can pull timing under boost and dial it in precisely without changing chips. Made 480 hp on pump gas with zero detonation.”
  • Tom K. (1969 Corvette, 540ci big-block): “I tried a competitor’s ignition box first. It failed after three months. My MSD box has been flawless for two years of hard street/strip driving. The build quality is miles ahead.”

Long-Term Reliability: Two Years and 15,000 Miles

I’ve now put 15,000 miles on this MSD ignition setup, including occasional track days and autocross events. The system has been completely trouble-free. I did open the distributor cap after one year to inspect the rotor—still looked new. The spark plug electrodes (NGK BKR7E gapped at .045) showed a consistent tan color across all eight cylinders, indicating even combustion. No signs of pre-ignition or crossfire.

One common question is whether the MSD system can handle the heat under a hood. I live in Phoenix, where summer temps hit 120°F. The control box has never overheated or gone into thermal shutoff. The coil does run warm to the touch, but that’s normal. MSD recommends spacing the coil away from exhaust manifolds if possible.

Maintenance Tips

  • Clean the distributor cap and rotor every 10,000 miles or once a year.
  • Check the ground wire connection for corrosion.
  • Replace spark plugs at the standard interval—MSD’s high-energy spark actually extends plug life by burning off deposits.
  • If you see a sudden misfire, test the coil with a multimeter (MSD provides resistance ranges in their manual).

Comparison: MSD vs. Other Ignition Systems

I’ve hands-on experience with five different ignition systems on performance engines: HEI, Accel, MSD, Bosch, and a crank-trigger system from Electromotive. Here’s a quick breakdown of where MSD excels.

FeatureMSD 6AL-2HEI (stock type)Accel 300+Bosch Motorsport
Max rpm12,000+~7,00010,0009,000
Programmable timingYes (3D table)NoYes (limited curves)No (mechanical only)
Built-in rev limiterDual stageNoSingle stageNo
Spark energy at 8,000 rpm~120 mJ~50 mJ~90 mJ~70 mJ
Field-replaceable modulesNo (sealed unit)YesYesNo
Price range (box only)$300–$400$60–$120$200–$300$500+

The MSD 6AL-2 offers the best balance of advanced features, spark energy, and price for a street/strip build under 600 HP. For higher-horsepower builds with forced induction or nitrous, systems like the MSD Digital 7 or the Grid system provide even more control, but the 6AL-2 is more than adequate for a 400 HP naturally aspirated engine.

Tuning Tips for Maximum Performance

Getting the most out of an MSD ignition isn’t just about bolting it on. You’ll want to adjust the timing curve to match your engine’s camshaft, compression ratio, and fuel octane. Here are the parameters I optimized.

Initial Timing

Start with the factory recommendation for your engine (typically 8–12 degrees for a small-block Chevy). Then gradually increase the initial timing until idle vacuum reaches its highest point, but stop before starter kickback becomes an issue. I ended up at 14 degrees initial with 34 degrees total by 3,000 rpm.

Total Timing

Set the total mechanical advance between 32 and 36 degrees, depending on cylinder head design and fuel quality. Avoid exceeding 38 degrees on pump gas with a 10.5:1 static compression ratio—you’ll risk detonation.

Vacuum Advance (If Applicable)

The 6AL-2 doesn’t use a conventional vacuum canister. Instead, you can use the manifold vac input in the software to add timing at light throttle. I added 10 degrees of timing when vacuum exceeded 14 inches Hg, which improved highway fuel economy by about 2 mpg.

Rev Limiter Settings

For street driving, set the soft rev limit about 200 rpm below the limit you’d set for peak power. This prevents accidental over-revving in gear. I used 6,500 rpm for the soft limit and 7,200 rpm for the hard limit—a safe margin for my forged rotating assembly.

MSD’s software downloads page has the latest version of the Power Pro software and detailed help files. I’d recommend spending an afternoon playing with the software before finalizing your tune.

Common Questions from Fellow Builders

After writing about my experience on a few forums, I’ve fielded many questions. Here are the answers to the most frequent ones.

Will an MSD ignition improve my fuel economy?

Yes, but indirectly. A more complete burn allows a leaner cruise mixture without misfire. If your carburetor or EFI system can deliver a lean mixture, you’ll see efficiency gains. But the system alone won’t fix a poorly tuned engine.

Do I need a crank trigger?

For a 400 HP build, the factory distributor-based trigger is sufficient. I would only recommend a crank trigger for engines that rev past 8,000 rpm or have severe harmonic vibration. The magnetic pickup in the MSD Pro-Billet distributor is very stable.

Is the MSD system compatible with aftermarket EFI?

Absolutely. I have a Holley Sniper EFI paired with the MSD ignition. You can use the EFI’s timing control output to command the MSD box. Holley provides detailed wiring guides for this configuration.

Can I use MSD with a points distributor?

MSD offers the 6A and 6AL boxes that work with points, but I recommend upgrading to an MSD distributor for reliability. Points bounce at high rpm and cause misfires even with a CDI box.

Final Verdict: Is the MSD Ignition System Worth It for a 400 HP Build?

After two years of driving, racing, and tuning, I can state this without hesitation: the MSD Ignition System was the single best upgrade I made to my 400 HP build. It turned a finicky, street-driven muscle car into a reliable, responsive machine that starts immediately, idles cleanly, and pulls hard all the way to the rev limiter. The installation required a careful weekend, but the instructions were clear and the support from MSD’s tech line was excellent.

For anyone building a high-performance engine—whether it’s a 300 HP street cruiser or an 800 HP race motor—the MSD system provides a foundation of reliable spark energy that you can tune to perfection. My only regret is not upgrading sooner. If you’re on the fence, I encourage you to make the switch. Your engine will thank you with every throttle stab.

Additional reading: The history of MSD in racing shows why their designs remain the standard.