LS-based engines factory installed into so many late-model Pontiacs are a hot rodder’s dream. The entire Gen III/Gen IV engine family is a straightforward yet effective design that’s been embraced by the aftermarket on many levels. A wide array of components intended to accentuate or significantly boost their already-impressive performance levels is readily available from many sources.
Like traditional Pontiac V-8s, the architecture among the entire Gen III/Gen IV family allows for easy component interchange. We contacted three companies on the forefront of late-model performance and asked each to share the intimate details of the LS-based engine package that’s most popular with Pontiac hobbyists. Installation into any Fourth-Gen Firebird, GTO, Grand Prix GXP, or G8 is relatively simple, requiring minimal modifications.
Follow along as we take an in-depth look at some of the engine packages that can be found powering many Pontiacs today. You might find one that fits your performance expectations, and budget too!
Mast Motorsports has been building Gen-IV engine packages for several years and it can be considered a one-stop shop for late-model GM performance. In addition to a complete line of aftermarket powertrain components such as cylinder heads and camshafts, Mast Motorsports also offers complete LS engines, and its LS3-based, 416-inch offering is very popular with Pontiac owners. Generating more than 600 hp, it offers consistent and reliable performance and installs easily into most any chassis.
Projected Output
Horsepower: 639 at 6,500 rpm
Torque: 554 lb-ft at 5,400 rpm
Block: Original GM aluminum LS3
Year: ’08 to current
Bore in Inches: 4.070-in
Cubic Inches Before/After Build: 376ci bored and stroked to 416ci
Bottom End
Pistons: Mahle flat-top with 4cc valve relief volume
Rings: Mahle
Rods: Callies Compstar, forged 4340 steel, 6.125-in length, 2.100-inch rod-journal diameter
Compression Ratio: 11.2:1
Crankshaft: Callies Compstar, forged 4340 steel, 4-in stroke
Mods: Balanced
Oiling System
Oil Pump: Melling, high-volume
Windage Tray: Mast Motorsports stroker
Oil Pan: Mast Motorsports LS conversion
Induction System
Air Filter: Mast Motorsports with IAT
Intake Manifold: Stock GM LS3 or FAST
Mass Air or Speed Density: Speed density
Throttle Body: GM LS3 90mm
Fuel Injectors: GM LS3
Fuel Management System: Mast Motorsports M120
Tuner: Mast Motorsports, Nacogdoches, Texas
Heads
Brand or Casting Number: Mast Black Label CNC for medium bore
Mods: CNC-machined, Mast proprietary design, 0.075 deck surface
Airflow Numbers: 361/247 cfm at 0.600 lift at 28-in of pressure
Valves: Mast Motorsports 2.165/1.6-in
Valvesprings: PAC dual springs
Pushrods: Mast Motorsports 8.05-in
Head Built By: Mast Motorsports
Camshaft
Brand: Mast Motorsport LS3 SS hydraulic roller
Duration at 0.050: 230/237-deg
Lift with Specified Rocker Arms: 0.608/0.615-in
Intake Centerline: 116-deg
Lobe Sep. Angle: 112-deg
Rocker Arms: Stock GM LS3, 1.7:1 ratio
Ignition
Type: GM Gen IV LS3
Coil(s): Stock GM
Wires: Mast Motorsports Black Label
Spark Plugs: NGK
Exhaust
Headers: Not included
Recommended: Muscle Rods tubular
Primary Size: 1.875-in
Collector Size: 3.00-in
Price and Part Number
$14,995 with control package PN 111-223 (ECM and harness)
Fits Which Chassis
Any LS-based Pontiac chassis
Options
A centrifugal Magnuson TVS 2300 ($7,000) adds 100-200 peak horsepower but offers increased power throughout rev range, and more than 500 lb-ft of torque just off idle.
Street Legal Performance (SLP) is a name that’s synonymous with late-model Pontiac performance since the late ’80s when it introduced a line of high-performance goodies for the Tuned Port engines in new Firebirds of that era. Within a couple of years, its Firehawk—a fire-breathing Firebird loaded with performance equipment—could be ordered through and delivered to your nearest Pontiac dealer. Since the discontinuance of Pontiac, SLP hasn’t sat idle. It continues to develop aggressive performance packages for many late-model GM vehicles. Its LS7-based, 427ci, long-block package proves a sound foundation for any Fourth-Gen Firebird, ’04-’06 GTO, or G8 GT, and is capable of generating 600 hp or more.
Projected Output
Horsepower: 600 at 6,500 rpm
Torque: 575 lb-ft at 4,500 rpm
(Note: achieved with L92/LS3 intake and 4-tube SLP headers)
Block
Block: GM Gen IV LS7
Year: New GM 7.0L
Bore in Inches: 4.125-in
Cubic Inches Before/After Build: 427
Bottom End
Pistons: SLP/Manley, forged 2618 aluminum
Rings: GM and Clevite
Rods: SLP/Manley, forged 4340 steel, 6.125-inch length, H-beam
Compression Ratio: 11.35:1
Crankshaft: SLP/Manley, forged 4340 steel, 4.00-in stroke
Mods: ARP cylinder head studs, GM MLS gaskets, GM lifters and guides, L92 pedestals, LS2 front cover and valley cover included
Oiling System
Oil Pump: SLP heavy-duty, ported and blueprinted
Windage Tray or Scraper: Not included
Oil Pan: Not included
Induction System
Intake Manifold: Not included
Recommended: L92/LS3
Mass Air or Speed Density: Mass Air
Airbox: Not included
Recommended: SLP Blackwing Cold-Air Induction Package for specific GM application
MAF: Not included
Recommended: Stock GM LS3
Throttle Body: Not included
Recommended: Stock GM LS3 or aftermarket 92mm
Fuel Injectors: Not included
Recommended: SLP 42-lb/hr
Computer (ECM): N/A
Fuel Management System: N/A
Tuner: SLP Performance Parts
Heads
Casting Number: GM L92/LS3, No. 12582714
Mods: As cast
Airflow Numbers: 330/202 cfm at .600-in lift at 28-in of pressure
Valves: GM 2.165/1.59-in
Valvesprings: SLP dual for 0.660-in lift
Pushrods: N/A
Heads Built By: SLP Performance Parts
Camshaft
Brand: SLP hydraulic roller
Duration at 0.050: 224/228-deg
Lift with Specified Rocker Arms: 0.591/0.600-in
Intake Centerline: 113-deg
Lobe Sep. Angle: 113-deg
Rocker arms: SLP, 1.85:1 ratio
Ignition
Type: Not included
Recommended: Stock GM LS3
Coil(s): Not included
Recommended: Stock GM LS3
Wires: Not included
Recommended: Stock GM LS3
Spark Plugs: Not included
Recommended: NGK TR-6 V-Power
Exhaust
Headers: Not Included
Recommended: SLP Long Tube, 4-tube
Primary Size: 1.75-in
Collector Size: 3.00-in
Price
$9,995
Fits Which Chassis
Any LS-based application
Options
Pushrods, installation kits, fuel injectors, double-row timing chains and L92/LS3 intake manifolds and 24- or 58-tooth reluctor ring all available separately. Available performance options include with SLP TVS 2300 Supercharger, 1.85:1 rocker arms, custom camshaft, lower compression ratio, 85-lb/hr injectors, boost-a-pump, custom blower pulley, custom mail-in tuning, windage tray spacers, and SLP long-tube headers. It’s also available as a short-block or in a 415ci variant.
If you own a Fourth-Gen Firebird and are seeking to improve its LS1’s performance without altering its stock appearance, Lingenfelter Performance Engineeing (LPE) has the perfect package. It’s specifically designed to significantly boost output without negatively impacting street manners or highway fuel economy. Simply make arrangements with LPE to deliver your Firebird to its Decatur, Indiana-based facility, and during the four-week turnaround, its original LS1 is removed, turned into a 383-inch beast generating 465 hp, reinstalled, and completely dyno tuned. LPE offers a similar service for other late-model Pontiacs, and can even provide complete mail-order engines for most any application.
Projected Output
Horsepower: 465 hp at 6,000 rpm
Torque: 440 lb-ft at 4,500 rpm
Block
Block: Stock Gen IV LS1
Year: ‘98 to ’02
Bore in Inches: 3.905-in
Cubic Inches Before/After Build: 346/383
Bottom End
Pistons: JE Pistons, forged aluminum, custom LPE spec
Rings: Total Seal custom
Rods: Manley, forged 4340 steel, I-beam, 6.125-in length
Compression Ratio: 11.01:1 (91 octane) to 11.5:1 (93 octane)
Crankshaft: Callies, forged 4340 steel, 4.00-in stroke
Mods: Custom preparation
Oiling System
Oil Pump: GM high volume, standard pressure
Windage Tray: Stock GM
Oil Pan: Stock GM F-body
Induction System
Intake Manifold: LS6, ported
Mass Air or Speed Density: Mass Air
Airbox: Whisper Air Lid, K&N filter
MAF: GM LS2 85mm
Throttle Body: Stock GM ported
Fuel Injectors (brand, size): GM/Bosch, 38-lb/hr
Computer: Stock ECM with modified calibration
Fuel Management System: Stock
Tuner: Lingenfelter Performance Engineering
Heads
Brand: Stock LS1 castings
Mods: CNC-ported, multi-angle valve job, surfacing
Airflow Numbers: 298/230 cfm at 0.600-in at 28-in of pressure
Valves: REV stainless steel, 2.02/1.57-in
Valvesprings: Comp Cams dual, No. 26921
Pushrods: Comp Cams
Heads Built By: Lingenfelter Performance Engineering
Camshaft
Brand: Comp Cams hydraulic roller, LPE custom spec
Duration at 0.050: 215/231-deg
Lift with Specified Rocker Arms: 0.629/0.643-in
Intake Centerline: 118-deg
Lobe Sep. Angle: 118-deg
Rocker arms: Stock GM, 1.7:1 ratio
Ignition
Type: Stock GM
Coil(s): Stock GM
Wires: Stock GM
Spark plugs: NGK TR6
Total Timing: 28-deg
Exhaust
Headers: Stock GM, cast-iron, F-body
Price
$15,995: The price includes removal from and reinstallation into the vehicle, chassis dyno testing before and after installation, LPE three-year/36,000-mile warranty, and LPE Certificate of Authenticity. LPE can perform a similar service to any LS1 and send back a crate engine that’s ready to run.
Fits Which Chassis
’98 to ’02 F-body
