Mangum Racing 267cc LS3 Cylinder Heads

Mangum Racing CNC Ported MR 15° LS3 Cylinder Heads

Built from our 6-bolt 15° LS3 casting featuring increased deck thickness, the MR 15° LS3 is engineered for serious naturally aspirated and boosted combinations that demand airflow, strength, and repeatability — while maintaining OEM valve angle and valve location geometry.

This casting is designed to support 1,500+ horsepower combinations when paired with the proper short block and induction system, making it an ideal solution for builders who need maximum performance without moving away from stock valve layout.

Each set is fully CNC ported in-house on new Centroid 5-axis machining centers and finished on Newen seat and guide equipment. Every cylinder head is hand blended, inspected, and assembled in small batches to ensure dimensional accuracy and consistency.

Airflow Performance

Tested on a SuperFlow bench with a 4.125” bore plate

Intake (Radius Entry)

• .200” – 148 CFM
• .300” – 227 CFM
• .400” – 282 CFM
• .500” – 325 CFM
• .600” – 350 CFM
• .700” – 363 CFM

Exhaust (No Pipe)

• .200” – 114 CFM
• .300” – 164 CFM
• .400” – 200 CFM
• .500” – 233 CFM
• .600” – 240 CFM
• .700” – 243 CFM

With a 267cc CNC intake runner and optimized 96cc exhaust port, the MR 15° delivers strong mid-lift efficiency and stable high-lift airflow — ideal for aggressive hydraulic roller and race-oriented camshaft profiles while retaining factory valve geometry.

Premium Hardware & Construction

• 6-bolt Mangum Racing LS3 casting with increased deck thickness
• 15° valve angle with OEM LS3 valve spacing
• 2.165” hollow stem stainless intake valves
• 1.600” hollow stem stainless exhaust valves
• Bronze guides
• PAC .660” dual spring package
• Titanium retainers
• Viton seals
• 1.250” steel spring seats
• 68.5cc CNC chambers (milling available at no charge)
• Chamber softening options for 4.000”, 4.065”, and 4.125” bore sizes
• Flat milling at .006” per cc
• Minimum bore: 4.000”

Built for High-Output Stock-Geometry Combinations

The increased deck thickness provides added durability under elevated cylinder pressure, while the 15° valve angle maintains compatibility with stock-style piston valve reliefs and factory-based valvetrain geometry.

The PAC .660” dual spring system offers the stability required for serious street or race camshaft profiles, and stock pushrod length works in many applications (final length should always be verified based on camshaft and milling).

For builders who need to retain OEM valve angles and locations but demand serious airflow capability, the MR 15° LS3 casting delivers.

Mangum Racing 273cc Qualcast LS7 Cylinder Heads

Mangum Racing CNC Ported 273 LS7 Cylinder Heads

Built from the Qualcast stock style replacement LS7 casting, the Mangum Racing 273 program is designed for high-rpm, large-displacement LS combinations that demand elite airflow and structural integrity.

Featuring a 12° valve angle and OEM LS7 valve spacing/valve length, this 6-bolt casting delivers exceptional port efficiency while maintaining compatibility with LS7-based platforms. With a 273cc CNC intake runner and optimized 93cc exhaust port, this cylinder head is engineered for serious naturally aspirated builds and high-output boosted applications where the customer wants a near bolt on cylinder head.

Each set is fully CNC machined in-house on our Centroid 5-axis machining centers and finished on Newen seat and guide equipment. Every head is hand blended, assembled, and inspected in small batches to ensure dimensional accuracy and repeatable performance.

Airflow Performance

Tested on a SuperFlow 1020 with a 4.125” bore plate

Intake (Radius Entry)

• .200” – 160 CFM
• .300” – 255 CFM
• .400” – 311 CFM
• .500” – 352 CFM
• .600” – 380 CFM
• .700” – 390 CFM

Exhaust (No Pipe)

• .200” – 117 CFM
• .300” – 160 CFM
• .400” – 209 CFM
• .500” – 221 CFM
• .600” – 230 CFM
• .700” – 244 CFM

The 273 LS7 delivers outstanding mid-lift efficiency with dominant high-lift airflow, making it ideal for aggressive street / strip combinations.

Premium Hardware & Construction

• 6-bolt Qualcast LS7 casting
• 12° valve angle with OEM LS7 valve spacing
• Stock Valve Lengths
• 273cc CNC intake port
• 93cc exhaust port
• 70.5cc CNC combustion chambers (milling available at no charge)
• 2.200” titanium intake valves
• 1.610” stainless exhaust valves
• Bronze CHE guides
• PAC .660” dual spring package
• Titanium retainers
• Viton seals
• 1.250” steel spring seats
• Chamber softening available
• Flat milling at .006” per cc
• Minimum bore: 4.100”

Designed for LS7 Street & Strip Builds

With airflow over 390 CFM at .700” lift, the Mangum Racing 273 LS7 is capable of supporting serious naturally aspirated horsepower in 427+ cubic inch combinations.

Stock pushrod length works in many applications but should always be verified based on camshaft selection and final milling.

Mangum Racing 275cc 11° LS3 Cylinder Heads

Mangum Racing CNC Ported MR275 11° LS3 Cylinder Heads

Built from the Mangum Racing 6-bolt 11° LS3 casting featuring a massive .750” deck surface, the MR275 is designed for maximum-effort naturally aspirated and boosted LS combinations where airflow, strength, and valvetrain stability are non-negotiable.

This casting was engineered for builders who want every available advantage — valve angle, deck thickness, port efficiency, and piston-to-valve clearance — all optimized to support serious compression and high cylinder pressure environments.

Each set is fully CNC machined in-house on brand new Centroid 5-axis machining centers and finished on Newen seat & guide equipment. Every head is hand blended, inspected, and assembled in small batches to ensure repeatability and precision.

Airflow Performance

Tested on a SuperFlow bench with a 4.125” bore plate

Intake (Radius Entry)

• .200” – 143 CFM
• .300” – 221 CFM
• .400” – 283 CFM
• .500” – 330 CFM
• .600” – 358 CFM
• .700” – 381 CFM

Exhaust (No Pipe)

• .200” – 112 CFM
• .300” – 161 CFM
• .400” – 202 CFM
• .500” – 232 CFM
• .600” – 242 CFM
• .700” – 248 CFM

With a 275cc CNC intake runner and optimized 98cc exhaust port, the MR275 delivers exceptional mid-lift efficiency with dominant high-lift airflow. The 11° valve angle significantly improves piston-to-valve clearance, allowing aggressive cam timing and higher compression strategies without compromise.

Premium Hardware & Construction

• 6-bolt Mangum Racing 11° LS3 casting with .750” deck thickness
• Optimized 11° valve angle and revised valve locations
• 2.185” hollow stem stainless extended-length intake valves
• 1.600” stainless extended-length exhaust valves
• Bronze guides
• Choice of PAC 1207X, 1208X, or 1209X dual spring packages
• Titanium retainers
• Viton seals
• 1.250” steel spring seats
• 70.5cc fully CNC chambers (milling available at no charge)
• Chamber softening options for 4.000”, 4.065”, and 4.125” bore sizes
• Flat milling at .006” per cc
• Substantial piston-to-valve clearance for advanced camshaft profiles and compression increases
• Minimum bore: 4.000”

Built for Maximum Effort Combinations

The increased deck thickness supports extreme cylinder pressure in large displacement and boosted applications. The revised 11° valve angle enhances airflow efficiency while providing additional mechanical clearance — a critical advantage in high-rpm, high-lift camshaft programs, or builds where smaller combustion chambers are required.

These heads have supported combinations exceeding 2,000 horsepower and 200+ mph in competition environments, making the MR275 a proven solution for serious LS3-based builds.

If you are building a no-compromise LS3 combination — naturally aspirated or power-adder — the MR275 was designed for exactly that purpose.

Mangum Racing Brodix 267cc LS3 Cylinder Heads

Mangum Racing CNC Ported Brodix 15° LS3 Cylinder Heads

Built from Brodix 6-bolt LS3 castings with extra deck thickness, our Mangum Racing 15° LS3 heads are designed for serious naturally aspirated and boosted combinations that demand airflow, strength, and repeatability.

Each set is fully CNC ported in-house with brand new Centroid 5-axis CNC mills and Newen seat & guide machines. Every set of cylinder heads is hand blended and carefully inspected before final assembly to ensure dimensional accuracy and consistency.

Airflow Performance

(4.125” Bore Plate)

Intake (Radius Entry)

• .200” – 148 CFM
• .300” – 227 CFM
• .400” – 282 CFM
• .500” – 325 CFM
• .600” – 350 CFM
• .700” – 363 CFM

Exhaust (No Pipe)

• .200” – 114 CFM
• .300” – 164 CFM
• .400” – 200 CFM
• .500” – 233 CFM
• .600” – 240 CFM
• .700” – 243 CFM

With a 267cc CNC intake runner and optimized 96cc exhaust port, these heads deliver strong mid-lift numbers with excellent high-lift stability — making them ideal for aggressive hydraulic roller street & race builds needing to retain the stock valve locations & angles.

Premium Hardware & Construction

• 6-bolt Brodix LS3 casting with increased deck thickness
• 15° valve angle, OEM LS3 valve spacing
• 2.165” hollow stem stainless intake valves
• 1.600” hollow stem stainless exhaust valves
• Bronze guides
• PAC .660” dual spring package
• Titanium retainers
• Viton seals
• 1.250” steel spring seats
• 68.5cc CNC chambers (milling available at no charge)
• Chamber softening options for 4.000”, 4.065”, and 4.125” bore sizes
• .006” per cc flat milling available
• Minimum bore: 4.000”

Designed for Builders Who Care About the Details

These are not mass-produced heads. Each set is machined, assembled, hand blended, and inspected in small batches to maintain strict quality control and dimensional consistency.

Extra deck thickness adds durability for higher cylinder pressure combinations. The PAC .660” dual spring setup provides valvetrain stability for serious cam profiles. Stock pushrod length works in most applications but should always be verified based on camshaft and final milling.

If you’re building a combination needing to stay stock valve angles & locations then this cylinder head is hard to beat!

Note: May require large bore master cylinder (sold separately) with a minimum 13/16" bore diameter for proper release.

Get access to even more vehicle data using PROLINK+ to wire in up to 2x analog signals and 1x CAN bus signal. Compatible with MPVI2+  MPVI3 and MPVI4 interfaces.

PROLINK+ Specifications:

• 2x dedicated 0-5V analog inputs.
• 1x CAN bus input (500kbps).
• 100Hz sampling rate.
• M8 connector to 5 wire harness.
• For MPVI2+ and MPVI3 interfaces.
• MPVI2+ interfaces must purchase Pro Feature Set to be able to use the PROLINK+ cable.

PROLINK+ for MPVI3 Devices

Since the latest generation MPVI3 interface is standard with Pro Feature Set, you only need to purchase the PROLINK+ cable to wire in these additional inputs. No other purchase is required.

PROLINK+ for MPVI Devices

To utilize the PROLINK+ cable with an MPVI2+ interface, the purchase of Pro Feature Set is required. PROLINK+ will be provided FREE of charge (plus shipping) with the purchase of Pro Feature Set for MPVI4 interfaces. However, if you would like additional PROLINK+ cables for multiple vehicles, you can purchase them on this page.

Pro Feature Set

Pro Feature Set enables the use of PROLINK+ for both MPVI2+ and the latest generation MPVI3. However, remember that MPVI3 is now standard with Pro Feature

Pro Feature Set also unlocks standalone data logging, allowing you to log directly to your interface’s internal storage without being tethered to a laptop. This highly convenient feature makes it easier than ever to collect data while on the road, track, or dyno.

Learn more details about Pro Feature Set.

• Install Height:   1.800"
• Closed Spring Pressure: 160 lb. @ 1.800" Installed Height
• Open Spring Pressure:  510 lb. @ 1.100" Height (.700" Lift)
• Maximum Spring Lift: .750"
• Coil Bind 1.000"

Precision Race Components all new cylinder head castings completed with 247cc runners. For 408 cubic inch and larger applications with 4.03"+ bore sizing.

Click Here to SEE why we build better heads!

• 247cc Fully CNC Ported Intake Runners
• 84cc Fully CNC Ported Exhaust Runners
• TSP Dual Spring Kit w/ PAC Springs Rated To .660" Lift
• 68cc CNC Machined Chambers
• CHE Bronze Guides
• 2.120" Intake / 1.600" Stainless Valves
• Factory Rocker Friendly!!*
• ***NOW AVAILABLE WITH HOLLOW STEM INTAKE VALVES!!! SAVES APPROXIMATELY 15 Grams!!!***

Click Here to SEE why we build better heads!

MADE IN THE USA!!
CAST IN THE USA!!
MACHINED IN THE USA!!

Flow Data (4.00" Flow Plate - No Exhaust Pipe):

The price listed is for you sending your cathedral port cylinder heads (4.8/5.3, LS1, LS6, LS2, LQ4/9) to us for porting. Our stage 1 porting service will include the re-use of the stock vales.  Stage 2.5 will include aftermarket 2.02/1.57 stainless steel valves. We also offer valve spring upgrades.

PRC CNC Porting/Machining Service Includes:

• Disassembly
• Deep Cleaning
• CNC Porting
• CNC Valve Job
• CNC Engraving of PRC Logos
• CNC Milling to Your Specs
• Reassembly
• Pressure Testing

Click Here to SEE why we build better heads! All Precision Race Components (PRC) cylinder heads come fully CNC-ported and machined using state-of-the-art technology. With all PRC cylinder heads, quality and performance are our two highest priorities! In addition to this, you will not find a better performing cylinder head porting service at this price.  Call one of our sales consultants today if you have any questions or if you would like to discuss your specific application.

*Typically a 1-2 week turn around time once heads arrive at our facility.

*Stage 1 porting NOT available for 4.8L and 5.3L castings due to the factory 1.94" intake valve size.  All 4.8L and 5.3L cylinder heads must select the stage 2.5 option that includes 2.02"/1.57" stainless steel valves!

Castings: 

• 4.8/5.3 (706/862)
• LS1 (241/853)
• LQ4/LQ9 (317)
• LS6/LS2 (243/799)

All Precision Race Components (PRC) cylinder heads come fully CNC-ported and machined using state-of-the-art technology!

Click Here to SEE why we build better heads!

MADE IN THE USA!!

CAST IN THE USA!!

MACHINED IN THE USA!!

PRC's aftermarket casting LS3/L92/L99 cylinder heads come standard with the following options:

• NEW PRC 13-Degree Valve Angle LS3 Castings
• Improved Piston-to-Valve Clearance For Extra Compression & Larger Camshafts
• Smaller Than Stock Intake Port Volume For Improved Port Velocity
• Manley Stainless 2.185" Intake, 1.60" Exhaust Valves
• Billet Rocker Pedestals
• TSP .660" Dual Spring Kit w/ PAC Valve Springs, Titanium Retainers, Seats, & Seals
• CHE Bronze Guides
• Completely Assembled and Milled to Your Specifications
• 60-68cc Chambers

All PRC cylinder heads are extensively researched and tested. The all-new PRC aftermarket casting LS3 cylinder heads are designed to flow considerably more than a gm ported casting while keeping the port sizes smaller for improved port velocity. The result is a cylinder head that is smaller than a stock GM LS3 port and moves more air than any other ls3 cylinder heads! 

The all new PRC aftermarket casting LS3 heads are the perfect option for customers looking for the ultimate in LS3/L99/L92 cylinder head technology

The PRC aftermarket casting LS3 cylinder heads are available in 2 different configurations: 

• 255cc Runners for max effort stock cube LS2/LS3/L99/L92 engines looking for a 370cfm cylinder head that can be aggressively milled & still keep better than stock p/v
• 260cc Runners For LS3/L99/L92 stroker engines needing a 380cfm+ cylinder head!

The 13-degree valve angle will allow for the ability to run more compression and larger camshafts thanks to additional piston-to-valve clearance!!  

With all PRC cylinder heads, quality and performance are our two highest priorities! In addition to performance, you will not find a better performing set of cylinder heads at this price (cost is for the pair!). Call one of our sales consultants today if you have any questions or if you would like to discuss your specific application. 

• 2.165"/1.59" Valves
• PRC Double Spring Kit AVAILABLE
• Completely Assembled & Setup To Your Specs!!

• Cylinder Head Cleaning
• CNC Valve Job
• CNC Porting
• Milling to customers specs
• Fully Assembled

*Typically a 1-2 week turn around time once heads arrive at our facility.

• Based off PRC's CNC Ported LS7 Heads
• 2.200"/1.610" Valves (base price for exchange includes new stainless exhaust valves)
• Available with PRC Double Spring Kit Complete With PRC Double Springs, Titanium Retainers, Seats, & Seals
• Completely Assembled & Setup To Your Specs!!
• Available With Stainless, Hollow Stems, or titanium valves!

Precision Race Components LS7 CNC 265cc ported cylinder heads.

Precision Race Components is proud to introduce our CNC porting service for your 5.3L & 6.2L LT1 cylinder heads! We do offer CNC cylinder head porting for those customers wanting to send their cylinder head castings to us for complete porting, competition 5-angle valve job, and professional assembly. This service does NOT include the cylinder head castings, only the porting, competition valve job, professional assembly, vacuum testing, and milling to the customer's specs. The PRC ported gen 5 L83 & LT1 cylinder heads are an excellent upgrade for customers looking for more power than what the factory castings offer. Pair our PRC ported gen 5 cylinder heads up with a TSP LT1 or L83 camshaft that was designed on our SuperFlow engine dyno for maximum power! Ask your sales professional how you can gain 100+ HP today!

This is sent when there is a parts change or after fixing mechanical issues that require us to start logging and adjusting again. Also we allow 2 weeks' grace from when we get started, and after that, we do send this 

MOT helps you pinpoint and troubleshoot issues with your car or truck and helps you move forward. We understand circumstances change; however, mechanical issues outside of the tune add an endless amount of time and days of email/phone communications, step-by-step walking customers through their issues.

To ensure great service, we have created an "After Tune Data Log and Tech Support Service". We do offer support for customers during the original tuning stages; however, with time and changes... issues happen. When issues happen, after the original tune, we can now provide you with amazing tech support that will ensure you get the support you need. This will allow you to get the same great service in helping you troubleshoot and fix issues when sending in data logs.  

This is an option on our Email/MOT Tunes.

DO NOT PURCHASE, you will be refunded. :) 

This is an option on our Email/MOT Tunes.

DO NOT PURCHASE, you will be refunded. :) 

This product is not eligible to be sold to California residents due to EPA restrictions.

This product is not eligible to be sold to California residents due to EPA restrictions.

Roto-fab 2016-19 Camaro SS cold air intake system with dry filter and  “sound tube delete” option. This option eliminates the sound tube assembly from the inlet elbow all the way back to the fire wall. The package features a smooth inlet elbow with no sound tube provision and a block-off plate for the sound tube entry in the firewall.

After 8 months of development, we are proud to announce the release of the Roto-fab 2016-19 Camaro SS cold air intake system.  This package delivers great performance and awesome sound without a tune or any modifications to the vehicle. Installation is easy and detailed, step-by step color instructions are included.

The Roto-fab 2016-19 Camaro cold air intake system uses all of the available real estate to package a huge air box and massive filter while maintaining an extremely effective barrier against engine bay heat. We’ve developed this intake to perform well as a “stand alone” mod while being capable of meeting the higher air demands of supercharged and high HP builds.

Our open top design effectively seals to the hood which maximizes air box volume while providing all of the advantages of a lid. We use top quality components throughout including high gloss silicone hose couplers, stainless steel hose clamps, stainless steel fasteners, molded-in inserts for air box and MAF sensor mounting and high quality filters designed to last for the life of the vehicle. The air box and duct work are custom molded to maximize air flow and fit the car perfectly. The logo badge on the air box has a black anodized finish with a laser etched Roto-fab logo. We also include a red Roto-fab vinyl graphic in the instructions giving end users the option of reversing the badge and applying the red logo to match the red lettering on the engine covers.

Please note this listing is for the dry filter option!

We are also offering the Roto-fab 2016-19 cold air intake system with accommodations for the sound enhancement feature in the car.

7-10 business days to build

• Furnace-Brazed Fins
  
• Needle Bearings
  
• Hardened Pre-Ground Pump Hub
  
• Computer Balanced
  
• Installation Hardware Included