Mangum Racing 273cc LS7 Cylinder Heads

$3,299.99

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 273cc LS7 Cylinder Heads - MailOrder Tuner

PRC LS7x 265cc CNC Small Bore Heads

$3,935.99

Requires at least a 4.065" Bore

Precision Race Components LS7 CNC 265cc ported cylinder heads.

Click Here to SEE why we build better heads!

MADE IN THE USA!!

CAST IN THE USA!!

MACHINED IN THE USA!!

PRC 6-Bolt LS7 Cylinder Heads with Thicker Deck Surface
Will Work on Both Standard GM 4-Bolt & Aftermarket LSx / RHS 6-Bolt Style Engine Blocks
2.205"/1.59" Valves
TSP .660" Dual Spring Kit w/ PAC Springs, Retainers, Seats, & Seals
Springs, Titanium Retainers, Seats, & Seals
CHE Bronze Guides
Completely Assembled & Setup To Your Specs
Available With Stainless Steel, Hollow-Stem, or Titanium Intake Valves
68cc Chamber Size as Standard

Extensive CNC and dyno testing has resulted in one of the most affordable and powerful LS7-based cylinder heads available! Flowing up to 35 CFM more than the stock GM LS7 head, the all-new PRC cylinder heads offer both unmatched power and airflow!

The PRC Small Bore LS7 cylinder heads are designed for both stroker, and stock cube applications with a 4.060"-4.100" bore. For bores larger than 4.100" bore checkout the PRC LS7 265cc & 285cc cylinder heads!

The PRC LS7 cylinder heads are available with hollow-stem intake and titanium intake valves. We recommend no more than .625" total intake valve lift with the hollow-stem intake valves and no more than .670" total valve lift with the titanium intake valves.

Superflow 600

	PRC 265cc LS7 Intake	PRC LS7 Exhaust
.200	169	118
.300	246	176
.400	304	208
.500	348	221
.600	380	230
.650	383	235
.700	388	240

**Valve spring lift ratings are based on using titanium intake valves.

PRC LS7x 265cc CNC Small Bore Heads , TFS LS7 Heads , BTR - Mail Order Tune

PRC LS7x 265cc CNC Heads

$3,935.99

Precision Race Components LS7 CNC 265cc ported cylinder heads.

Click Here to SEE why we build better heads!

MADE IN THE USA!!

CAST IN THE USA!!

MACHINED IN THE USA!!

PRC 6-Bolt LS7 Cylinder Heads with Thicker Deck Surface
Will Work on Both Standard GM 4-Bolt & Aftermarket LSx / RHS 6-Bolt Style Engine Blocks
2.200"/1.610" Valves
TSP .660" Dual Spring Kit w/ PAC Springs, Retainers, Seats, & Seals
Springs, Titanium Retainers, Seats, & Seals
CHE Bronze Guides
Completely Assembled & Setup To Your Specs
Available With Stainless Steel, Hollow-Stem, or Titanium Intake Valves

Extensive CNC and dyno testing has resulted in one of the most affordable and powerful LS7-based cylinder heads available! Flowing up to 35 CFM more than the stock GM LS7 head, the all-new PRC cylinder heads offer both unmatched power and airflow!

The PRC LS7 cylinder heads is available with standard stainless valves, hollow-stem intake, and titanium intake valves. If you are going to run the stainless steel intake valves, we recommend limiting total valve lift to no more than .616" due to the weight of the intake valve. Upgrading to the hollow-stem intake valve will shed significant intake valve weight and allow for additional lift. The titanium intake valves will be the lightest choice of the three choices and offer the best lift possible!

Flow Data: @ 4.125" Bore Plate Superflow 600

	LS7 Intake	LS7 Exhaust	PRC 265cc LS7 Intake	PRC LS7 Exhaust
.200	161	114	169	119
.300	227	171	248	179
.400	291	193	308	211
.500	330	203	351	224
.600	351	209	383	235
.650	353	204	388	241
.700	353	209	393	246

**Valve spring lift ratings are based on using titanium intake valves.

PRC LS7x 265cc CNC Heads , BTR LS7 heads , LS7 Heads - Mail Order Tune

LS7 heads , PRC heads , Texas speed and Performance, Manley valve , CHE guides - Mail Order Tune

PRC 247cc CNC Ported Cylinder Heads

$2,774.39

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!

MADE IN THE USA!!

CAST IN THE USA!!

MACHINED IN THE USA!!

Features:

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!!!***

The all new 247cc cylinder head is finally available for customers looking for the pinnacle of LS cathedral port performance. The new 247cc port has been flow bench tested to flow over 360cfm.

Flow Data:

No Exhaust Pipe

LIFT	INTAKE FLOW	EXHAUST FLOW
.100"	66 CFM	57 CFM
.200"	147 CFM	117 CFM
.300"	228 CFM	170 CFM
.400"	282 CFM	206 CFM
.500"	321 CFM	227 CFM
.600"	343 CFM	235 CFM
.650"	355 CFM	241 CFM
.700"	360 CFM	245 CFM