GM Performance LSX376-B15 crate engine equipped with a Magnuson TVS supercharger

🔹 Engine Overview – LSX376 B15

Manufacturer: Chevrolet Performance
Platform: Gen IV LS / LSX series
Displacement: 376 cu in (6.2L)
Induction: Magnuson TVS2300 positive-displacement supercharger
Rated Output:
~720 hp @ 6,600 rpm
~685 lb-ft @ 4,500 rpm
(Power varies with pulley size, exhaust, and tuning)
Intended Use: Drag & street performance, pro-touring builds, restomods, kit cars.

🔧 Core Specifications

Item. Details

Block. GM LSX cast-iron high-strength

Bore x Stroke. 4.065″ x 3.622

Compression Ratio. 9.0:1 (boost-friendly)

Crankshaft. Forged steel
Connecting Rods. Forged powdered metal / upgradeable

Pistons. Forged aluminum, coated

Heads. LSX-LS3 style aluminum rectangle port

Camshaft. Hydraulic roller, boost-specific

Supercharger. Magnuson TVS2300, integrated intercooler

Fuel System. High-flow injectors, return-style recommended
ECU. Requires standalone or GM Connect & Cruise

⚙️ What Makes the B15 Special
Built specifically for 15 psi boost (hence “B15”)
Heavy-duty LSX block handles 1,000+ hp potential
Factory-engineered blower calibration baseline
Excellent street manners with instant torque
More reliable than turbo setups for daily use

🧠 Real-World Reviews & Feedback
Pros 👍

Brutal low-end torque – feels like a big-block with modern manners
Turn-key reliability when tuned correctly
TVS blower gives instant boost (no lag like turbos)
Handles heat better than many aftermarket builds
OEM-level drivability and cold starts

Cons 👎

Needs strong fuel system (dual pumps recommended)
Tight engine bay clearance in some swaps
Requires premium fuel only
Cooling system must be upgraded

Common Owner Comments

“Pulls from 2,000 rpm like a freight train.”
“More reliable than my old turbo LS build.”
“Best street engine I’ve owned—starts like stock but hits like a race motor.”
“Cooling and traction are the real challenges, not power.”
🚗 Recommended Transmissions

Manual Options
Tremec T56 Magnum

Best overall street/strip choice
Rated 700 lb-ft
Great aftermarket support
Perfect for Camaro, Chevelle, C10 swaps

Tremec TKX

Compact fit
600 lb-ft rating
Excellent for older chassis with tunnels

Automatic Options

4L80E (Most Popular)
Handles 800+ hp with build
Affordable & proven
Great for drag/street
6L80 / 6L90
Modern 6-speed
Needs standalone TCM
Excellent drivability
TH400 (Race)
Bulletproof
Not ideal for highway without OD

🧩 Supporting Mods Recommended

90–102mm throttle body
Dual 340lph or brushless fuel pump
80–100 lb injectors (depending on pulley)
3.5″ exhaust minimum
Upgraded radiator & oil cooler
9.5″+ rear differential (Ford 9″, 12-bolt, Dana 60)

🛠 Ideal Vehicle Fits

1967–73 Camaro / Firebird
C10 trucks
Chevelle / Nova
Foxbody & SN95 swaps
Restomod classics
Factory Five & kit cars