Inside Look at Golen’s 427 LSx Crate Engine: Boosted to 1000 HP

Hey everyone, Chad Golen here from Golen Engine Service. I’m excited to give you the full scoop on our 427 LSx Crate Engine that’s boosted—a real beast that pumps out over 1000 horsepower and 900 ft-lbs of torque. We’ve been building high-performance LSx crate engines for over 20 years here in Hudson, New Hampshire, and this one’s a testament to what we can do when we put our minds to it. It’s got the power to rule any road, the guts to handle tough jobs, and the finesse to keep things tame when you’re just cruising. Let’s break it all down—how it runs, how we machine it, the parts I’ve picked, and how we bring it to life in the shop.

A Performance 427 LSx Crate Engine That Packs a Wallop

This 427 LSx crate engine is built to deliver, and it doesn’t disappoint. With the Whipple 3.0L Super Charger strapped on, it’s pushing 1000hp and 900 ft-lbs of torque—numbers that can turn a GM truck or car into a force of nature. I’ve taken this engine out myself, and it’s something else. At low speeds, it’s smooth and easygoing—idling through town or crawling in traffic, it behaves like you’d expect from a street engine. You wouldn’t guess there’s a monster under the hood. But when you mash the gas, it’s game on. The boost hits hard, the tires fight for grip, and you’re pinned back with a grin you can’t shake. That’s what I love about it—big power when you call for it, good manners when you don’t. It’s perfect for guys who want a daily driver that can double as a track star or a tow rig with attitude. I’ve had customers tell me it’s the best of both worlds, and I agree—it’s why I keep building these.

Machining: Where We Lay the Groundwork

You don’t get to 1000hp without starting strong, and that’s where our machining and quality components come in. We kick things off with the Dart SHP Cast Iron Race Block, a foundation tough enough to take the heat of a boosted build like this. Here’s how we get it ready to rumble:

• CNC Machining the Block: First step is loading that Dart block into our Rotler 4-Axis CNC. This machine’s a workhorse—cuts through cast iron like butter, shaping the bores, deck surfaces, and every critical area with precision you can count on. At 1000hp, tolerances matter, and this CNC delivers. We’ve been using it for years because it’s reliable, and I trust it to set up the block right every time.
• Honing Cylinders: After the CNC, the block heads to our Sunnen SV-15 Hone with diamond finishing stones. This isn’t just about making things pretty—it’s about getting the cylinders ready for our stainless steel piston rings. We hone them to a perfect crosshatch pattern, which helps the rings seat and seal under boost. We check every cylinder with a Total Seal Profilometer, measuring the finish to make sure it’s dead-on. Too rough or too smooth, and you’re asking for trouble—blow-by, oil burning, you name it. I’ve seen engines fail over less, so we don’t skip this step.
• Blueprinting Everything: We measure and record it all—bore diameters, centerline alignment, deck height. It’s all blueprinted, written down, and double-checked. At this power level, there’s no room for slop, and we make sure every spec is locked in before we move on.

Then there’s the Golen Engine Aftermarket 6-Bolt LS Heads—these are the lungs of this engine.

• 5-Axis CNC Porting: We put the heads in our Centroid 5-Axis CNC machine for a full port job that gets them flowing 380 cfm. This is where we get the airflow cranking—big ports, smooth paths, all designed to feed that Whipple Super Charger. It’s a game of inches, but it adds up to hundreds of horsepower when you get it right.
• Guides and Valve Job: We start by finishing the bronze guides, then move to our Sunnen VGS-20 Seat and Guide Machine for a 3-angle valve job. This is important to ensure air flows into the engine properly to make this power level.
• Head Surfacing: Back to the Rotler CNC for the final touch. We resurface the heads to hit the exact RA—roughness average—that mates perfectly with the Cometic MLS Head Gaskets. No leaks—just a seal you can trust when the boost cranks up.

We wrap up machining by balancing the rotating assembly in our CWT Balancer. The Callies Comp Star 8-counterweight crankshaft and Comp Star Extreme 6.125″ rods line up with the Wiseco 2618 Forged Boost pistons. It’s a tight fit, and we balance it to the gram—for smooth power all the way to redline.

Golen Engine 427 LSx Crate Engine Parts I Stand Behind

Here’s the lineup I’ve chosen for this 427 LSx Crate Engine—it’s all top-tier stuff built to handle the job:

• Dart SHP Cast Iron Race Block: This block’s a tank—cast iron that can take the pounding of 1000hp and boost without flinching.
• Callies Comp Star 8-Counterweight Crankshaft: Forged steel, eight counterweights for stability
• Callies Comp Star Extreme 6.125″ Rods: These rods are able to handle up to 1400hp per Callies
• Wiseco 2618 Forged Boost Pistons: With GFX rings and tool steel wrist pins—these pistons are made for boosted applications
• King Main and Rod Bearings: Performance bearings that measure the same every time you use them
• BTR Stage 3 PD Hydraulic Camshaft: I went with this cam and Johnson Hyd tie-bar lifters #2116LSR for reliability and good performance on the street
• Cloyes Billet Timing Set: The C5R chain keeps timing locked in!
• Melling High Volume Oil Pump #10296: Plenty of oil flow to keep things cool and lubed.
• Cometic MLS Head Gaskets: Multi-layer steel for a bulletproof seal—I trust these to hold up.
• ARP Head Studs: These studs clamp it all down tight—no lifting heads at 1000hp.
• BTR Shaft Mount Rocker Arm System: A solid valvetrain setup!
• Hardened BTR Pushrods: .083” 5/16, never an issue which is nice!
• Whipple 3.0L Super Charger: This is the big gun, driven by a Wegner billet front drive system with a dedicated belt that won’t slip, no matter how hard you push!

Every part’s American-made where possible—I’ve built Golen Engine Service on quality, and these components deliver.

Assembly and Testing: Bringing It to Life

We assemble this crate engine by hand, and I’m right there with the team. Every clearance—main bearings, rod journals, thrust—is blueprinted to the tenth. I check the torque on every bolt myself—head studs, mains, rods—because 1000hp doesn’t forgive mistakes. We start with an NA break-in on our Super Flow Engine Dyno, no supercharger yet. This seats the rings and lets us watch the vitals—oil pressure, coolant temp, power curve. I’m looking for steady numbers, no leaks, no hiccups. It’s got to be right before we move forward.

Once it’s broken in, we bolt on the Whipple 3.0L Super Charger and hook up the Holley Terminator X-Max EFI system. I handle the tuning in-house, sitting at the dyno with my laptop, tweaking fuel maps and boost timing. It’s a process—dialing in the air-fuel ratio, watching the boost climb, making sure it pulls hard without leaning out. We don’t stop until it’s clearing 1000 hp and still drives like a dream at low throttle. That’s the Golen way—power you can use, not just brag about. We allow our customers to come see the engine in person so they can get the full experience and get some video to show their friends!! This keeps them fully enthused in the project!!

This boosted 427 LSx Crate Engine is a Golen Engine firing on all cylinders—over 1000hp and 900 ft-lbs of torque, built to run easy or hit hard. It’s got the low-speed control I insist on and the power I love to unleash. We’re not here to mess around—we build engines that work, period. If you want one of these under your hood, give us a call at 1-800-591-9171 or head to www.golenengineservice.com. Let me know what you think—would this beast fit your ride?