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Making power with an LS: build recipes

Proven paths from stock to 400, 500 and 600+ hp, what an AFM engine needs first, and what to upgrade along the way.

Last updated November 2, 2026

How we put this guide together

Engine building was the second-biggest category in our research: 323 of the 2,012 LS swap questions we pulled from forum threads were about making more power. People want to know what a cam alone is worth, whether a junkyard 5.3 will take boost, and what has to change on an AFM engine.

Step 1: Know your starting point

Rough numbers for stock engines: a 5.3 makes around 320 hp / 340 lb-ft and a 6.0 around 300 hp / 360 lb-ft, depending on version and year. That's a generalization; individual engine codes differ (the LQ9 6.0 is rated 345 hp, for example). Check yours on its engine page.

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Step 2: Check for AFM before you buy a cam

Many Gen IV engines have Active Fuel Management (AFM), which shuts off four cylinders using special lifters fed oil through the valley cover. An aftermarket cam means a full AFM delete:

a non-AFM camshaft
all 16 conventional roller lifters, not just the 8 AFM ones
new lifter trays
blocking the deactivation oil circuit, plus a tune

More: what a full AFM/DOD delete involves.

Just plugging the oil passages and keeping the AFM lifters is not a delete: the collapsible mechanism stays, and oil can back-feed and collapse lifters later. Also add GM's oil pan pressure-relief-valve cap (12639759) to stop oil spray and consumption, and replace the pickup O-ring. AFM engines use a single-bolt cam, so a three-bolt performance cam needs a matching three-bolt gear and chain.

Step 3: Pick your path by power target

These are proven recipes (the full parts lists are in the table below):

Target	5.3 path	6.0 path
About 400–450 hp	Cam swap (Truck Norris-style), or cam + intake + throttle body	—
500–550 hp	Nitrous plate kit	Cam + intake (500); bigger cam (550)
600 hp	Turbo kit, or nitrous	Heads + cam + intake (a rectangle-port conversion)
700 hp	Turbo + valvetrain upgrades	Supercharger
800 hp+	—	Turbo (E85 required at this level on the stock bottom end); forged pistons and rods for about 1,000 hp

Two real-world data points from project engines: a junkyard LM7 5.3 made 430 hp with a simple cam swap (BTR Truck Norris, in a C10), and a 6.0 LQ9 with fresh pistons, rings, bearings and a COMP cam made 496 hp / 460 lb-ft (in a Chevelle).

Step 4: Upgrade what the extra power will find

Each step up puts load on something else:

Valve springs come with almost every cam recipe above, because a bigger cam's lift and rpm are past what stock springs control; some cams (NSR versions) are designed to run on stock springs. More: how to pick valve springs for a cam.
Fuel: at about 400 hp a 5.3 is near the limit of the stock injectors and fuel system, and the stock filter/regulator tops out around 450 hp. See the fuel guide.
Oil pump: the factory pump cavitates above about 6,200 rpm (flow drops nearly 1 GPM by 7,000 rpm). Don't shift above 6,200 rpm on a stock pump. High-volume pumps such as the Melling 10296 aren't automatically better: in racing they can empty the sump faster and speed up oil starvation. More: which Melling pump for a cam swap.
Trunnions, lifters and timing chain show up in the 450 hp+ recipes (trunnion upgrade kits, LS7 lifters, new chain).

Step 5: Tune it

A cam, injectors, boost or an AFM delete all need tune changes. The tune checklist lists what yours needs, and the cam finder shows what each cam asks for in converter, springs and idle.

Full parts lists for every recipe are below. Spot something that's changed? Tell us.

Recipes, dyno charts and build facts

LS1 cam owner-reported results (exploratory) — Owner-reported, unverified forum data.

Build recipes

Engine	Target	Method	Parts	Notes
5.3	400	cam swap	BTR Truck Norris cam (or NSR version for stock springs) BTR valve springs GM balancer bolt Fel-Pro timing cover gasket set	Near the limit of stock injectors/fuel system at this level
5.3	450	cam + intake + TB	Edelbrock Rollin Thunder cam PAC 1218 valve springs PRW trunnion upgrade kit Edelbrock LSX 92 mm intake Holley Sniper 92 mm throttle body
5.3	500	nitrous	Holley Sniper wet nitrous plate kit, LS, 80 mm 3-bolt (100/125/150 hp jets; up to 175 hp)
5.3	600	turbo	VS Racing Nex Gen 7875 turbo VS Racing 50 mm wastegate Hooker single turbo exhaust manifold kit 3 in intercooler pipe kit 3 in inlet/outlet intercooler
5.3	600	nitrous	Holley Sniper wet nitrous plate kit (100–150 hp jets, up to 175 hp)
5.3	700	turbo + valvetrain	Elgin Sloppy Mechanics Stage 2 cam Full LS gasket set LS 12-point head stud kit LS7 roller lifters (x2 sets) LS7 lifter trays (x4) GM replacement timing chain
6.0	500	cam + intake	COMP Stage 2 Thumper Master cam kit Edelbrock Pro-Flo XT RPM intake Fel-Pro timing cover gasket set Chevrolet Performance balancer bolt PRW trunnion upgrade kit LS7 lifters (x2) + trays (x4) GM timing chain Holley Sniper 92 mm TB	TrailBlazer SS intake needs OEM or aftermarket fuel rails
6.0	550	cam	Elgin Sloppy Mechanics Stage 3 cam kit
6.0	600	heads + cam + intake	Flo-Tek LS3 heads (x2) BTR Equalizer 3 intake FAST 65 lb/hr injectors COMP Stage 2 LS3 hydraulic roller cam BTR Platinum dual valve springs Holley 102 mm TB ARP 2000 head studs Speedway premium gasket kit COMP BSR shaft rockers COMP Hi-Tech pushrods	Rectangle-port conversion
6.0	700	supercharger	Edelbrock E-Force Gen 3 LS supercharger kit E-Force 3.00 in and 2.75 in pulleys BTR Stage 2 LS cam COMP beehive valve springs
6.0	800	turbo	VS Racing VSR-400 80 mm turbo Hooker single turbo manifold kit BTR Equalizer intake COMP LST Stage 2 cam BTR dual springs VS Racing 50 mm wastegate FAST 85 lb/hr injectors Holley Sniper 102 mm TB LS gasket set GM balancer bolt	E85 required at this level, especially on the stock bottom end
6.0	1000	turbo + forged internals	Flowtech LS turbo headers VS Racing 44 mm wastegates (x2) Mahle PowerPak pistons BTR H-beam rods	Also bearings and rings per machine-shop specs

Build facts

Stock 5.3 is rated around 320 hp / 340 lb-ft; stock 6.0 around 300 hp / 360 lb-ft, depending on version and year (Engine table ranges differ by RPO (e.g., LQ9 345 hp); use per-RPO data where possible)
Junkyard LM7 5.3 made 430 hp with a simple cam swap (Speedway C10 project; BTR Truck Norris)
LS4 (2005–2009 FWD Impala SS/Monte Carlo SS/Grand Prix GXP) is not recommended for RWD swaps; different bellhousing bolt pattern among other issues
Gen IV AFM engines need an AFM delete to run aftermarket cams; many also delete VVT, which requires a Gen 3-style timing cover in place of the VVT cover with integrated phaser
Stock LS fuel filter/regulator assembly tops out around 450 hp; beyond that, larger lines and an external regulator
Project Chevelle LQ9: fresh pistons, rings, bearings and a COMP cam made 496 hp / 460 lb-ft
LFA/LZ1 hybrid 6.0s (aluminum, cathedral heads) are only recommended if nothing else is available; plan a different cam and custom accessory drive
AFM (introduced 2005 in Tahoe-class SUVs) deactivates both valves on four cylinders using oil-pressure-controlled lifters fed by the LOMA/VLOM valley-cover manifold
A proper AFM delete: non-AFM camshaft, all 16 conventional roller lifters (not just the 8 AFM lifters), new lifter trays, and blocking the deactivation oil circuit (non-AFM valley cover or plugs); heads must come off, so head gaskets, head bolts and exhaust gaskets too
Plugging the oil passages while keeping AFM lifters is not a delete: the collapsible mechanism remains and oil can back-feed into the DOD channels and collapse lifters later
Add GM oil-pan pressure-relief-valve cap (12639759) when deleting AFM to stop oil spray/consumption; replace the pickup O-ring
AFM engines use a single-bolt cam; a three-bolt performance cam needs a matching three-bolt gear and chain. Gen IV moved the cam sensor to the front cover
PCM must be recalibrated to stop commanding deactivation; aftermarket cams also need idle, fuel, spark and torque-model changes
Failing AFM lifter: single-cylinder misfire, persistent tick, rough idle, low power, cylinder-specific misfire code; can progress to bent pushrods, cam lobe wear and metal in the oil
Summit AFM delete kit (no cam) CMB-09-0026: 16 lifters, new lifter guides, head bolts, LS3-style valley plate
Speedway 5.3 guide calls the L33 a Gen IV engine and the LC9 an iron-block engine (GM engine tables list L33 as Gen III and LC9 as aluminum)
LS mount bosses are roughly where SBC mounts were; common adapters convert the LS block to the classic three-bolt Chevy mount; adapter hole offsets move the engine fore/aft
Junkyard LS pans often hang too low (sump depth) for muscle cars/hot rods; low-profile swap pans fit most chassis; baffled/ventilated pans help oil control in hard cornering
Accessory drive spacing: Camaro/F-body about 0.750 in farther from the block than Corvette; truck about 1.5 in farther
Most LS water pumps have both inlet and outlet on the passenger side; LS swap radiators put both ports on the passenger-side tank
Speedway: LS upper hose is 1-1/4 in (smaller than SBC/BBC) (The upper hose connection on all LS pumps may be 1-3/8 in)
LS thermostat sits low on the water pump, so a steam line is needed to purge trapped air; most LS swap radiators have a steam port, and adapters let universal radiators work
LS keeps the same bellhousing dowels and 5 of 6 bolt holes as SBC/BBC, but the crank flange sits farther forward; autos need a dished flexplate + converter sleeve adapter to run TH350/400/700R4; manuals need an LS-specific bellhousing (e.g., OER, Quick Time) for older 4-bolt GM or TKO boxes
Exception: 1999–2000 LQ4 6.0s have a "long" crank flange and use a flat flexplate with no dish or spacer
Crank reluctor is 24x or 58x; the ECU must match. Tell by the crank sensor (behind the starter): early black 24x, later gray 58x
LS can run a carburetor: Edelbrock Performer RPM / Victor Jr. carb intakes, Holley options, and an MSD standalone ignition box for the coil-near-plug ignition
LS EFI needs about 58 psi vs 5–7 psi for a carbureted small block; parts-store hose clamps/rubber hose are not adequate at 60 psi. Use AN hardlines, push-on hose/fittings, or ethanol-safe hose (e.g., Earl's Vapor Guard)
Follow ECU maker wiring exactly; go heavier on wire gauge when in doubt; soldered + heat-shrink connections beat cheap crimps
The PCM reads crank, cam, MAF, coolant, IAT and O2 sensors to control fuel, spark and idle (and shifts on automatics); on drive-by-wire engines it also controls the throttle
Every donor PCM needs reprogramming: delete VATS (or the engine will not start), match injector size and MAF scaling, and match transmission settings; emissions monitors and speed limiters from the donor are also present
24x (Gen III: LS1, LS6, LQ4, LQ9, Vortec trucks through 2006) uses a 1x cam sensor; 58x (Gen IV: LS3, LS7, L76, L92, 2007+ Vortec trucks, and the 58x LS2s: 2006–07 Corvette and CTS-V, 2007–09 TrailBlazer SS, 2008–09 Saab 9-7x Aero) uses a 4x cam sensor. Exception: the 2005 Corvette, 2005–06 GTO and SSR and 2006 TrailBlazer SS LS2s are 24x, so they need a 24x harness and computer. PCM, harness and sensors must match; a Gen III PCM on a 58x engine needs a conversion box
Gen III: black crank sensor, cam sensor at the rear of the block. Gen IV: gray crank sensor, front-mounted cam sensor, EV6-style injectors, six-pin drive-by-wire throttle
Drive-by-cable: throttle opened mechanically (early Gen III trucks, Camaro LS1). Drive-by-wire: PCM opens the throttle from a pedal-position sensor (all Gen IV). A DBW swap needs the pedal wired and calibrated (PSI also says "most LS1/LS6" are DBW; C5 Corvette LS1 was DBW while F-body LS1 was cable; treat per-application)
Very cheap (~$150) harnesses with thin wire and knockoff connectors cause intermittent misfires, no-starts or worse; quality standalones use proper-gauge wire (TXL), new Delphi connectors and are tested
A standalone harness keeps only the circuits the engine needs to run, removing body-specific donor wiring
Gen II LT1/LT4 (1992–1996) are not LS engines: cable throttle, EV1 injectors, different harnesses
Melling M295: stock-replacement LS pump, standard volume/standard pressure
Melling 10295: standard volume, higher pressure (upgrade with optional pressure springs)
Melling 10296: high volume, ~18% more flow than stock (~8 GPM vs ~6.8 GPM), ships with a stiffer spring (+10% max pressure / "+10 psi"), stock spring included; designed for single-roller timing chains (double roller may need timing-cover mods); for 1999–2016 4.8/5.3/5.7/6.0/6.2
Melling 10355: high-pressure pump for 2005–2017 Gen IV 5.3/6.0/6.2 with AFM and VVT (need higher pressure); +10 psi spring installed, stock and +20 psi springs included; 10355HV variant exists
Melling 10294: 15% LOWER volume, for aftermarket blocks with priority main oiling (GM LSX, Dart LS Next)
Factory LS oil pump cavitates above ~6,200 rpm (flow drops nearly 1 GPM by 7,000 rpm); avoid shifting above 6,200 rpm on a stock pump
High-volume pumps can accelerate oil starvation in racing by emptying the sump faster

Engine build questions

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