The potential to make power is relative to the flow of air going through your engine. After you have bolted on a killer exhaust and high-flow intake, how do you get more power out of your engine? Process of elimination - that's how! With all the bottlenecks removed from the intake and exhaust, you can now open up the heads and really see some noticeable power gains.

But, do you port and polish the stock heads, bolt on some aftermarket heads, or port some aftermarket heads? This would all depend on if you want the combination to pass smog, and how much power you care to build. Some engines don't have smog-legal aftermarket heads available for them, so porting the stock units may be your only choice. Maybe you don't care about smog and you're building the biggest engine you can make with your bottom end. Either way, here is a list of cylinder head manufacturers and some cool heads that will give you ideas about what is available on the market.

Air Flow Research
Product: LS1 205 or 225
Material: Aluminum
Head Fitment: LS1
Port Job: Mongoose 205/225
Combustion Chamber Shape: Heart
Combustion Chamber Volume (cc): 66/76
Intake Runner Volume (cc): 205/225
Exhaust Runner Volume (cc): 84/85
Intake Flow at 0.600 Lift with 28 Inches of Vacuum: 300/320 cfm
Other Applications: Ford, Chevy small- and big-block

For more information, contact:
Air Flow Research
(818) 890-0616
www.airflowresearch.com

Trick Flow
Product: Trick Flow Kenny Duttweiler Signature Series
Material: A356-T61 Aluminum
Head Fitment: Small-block Chevy
Port Job: CNC Duttweiler Series
Combustion Chamber Shape: Heart with 23-degree valve angle
Combustion Chamber Volume (cc): 64/72
Intake Runner Volume (cc): 195
Exhaust Runner Volume (cc): 72
Intake Flow at 0.600 Lift With 28 Inches of Vacuum: 258/249
Other Applications: Ford

For more information, contact:
Trick Flow Specialties
(330) 630-1555
www.trickflow.com

Barry Grant
Product: Triple D Induction Three Valve
Material: Aluminum
Head Fitment: Small-block Chevy
Port Job: As Cast
Combustion Chamber Shape: Clover
Combustion Chamber Volume (cc): Unknown
Intake Runner Volume (cc): Unknown
Exhaust Runner Volume (cc): Unknown
Intake Flow at 0.600 Lift With 28 Inches of Vacuum: Unknown
Other Applications: None

For more information, contact:
Barry Grant Inc.
(706) 864-8544
www.barrygrant.com

Brodix
Product: Ford Track 1 M2 18 STD X
Material: Aluminum
Head Fitment: Small-block Ford
Port Job: M2
Combustion Chamber Shape: Based off of the 351 W
Combustion Chamber Volume (cc): 64/68 cc
Intake Runner Volume (cc): 211
Exhaust Runner Volume (cc): Unknown
Intake Flow at 0.600 Lift With 28 Inches of Vacuum: 316 cfm
Other Applications: Small-block Ford, small- and big-block GM, Mopar

For more information, contact:
Brodix Inc.
(479) 394-1075
www.brodix.com

Dart
Product: 15-degree small-block Chevy
Material: Aluminum
Head Fitment: Small-block Chevy
Combustion Chamber Shape: Heart compact chamber
Combustion Chamber Volume (cc): 51
Intake Runner Volume (cc): 276
Exhaust Runner Volume (cc): 111
Intake Flow at 0.600 Lift With 28 Inches of Vacuum: 371 cfm
Other Applications: Street & Race heads for Chevy small- and big-block, Ford small-block, Honda B-series

For more information, contact:
Dart Machinery
(248) 362-1188
www.dartheads.com

Edelbrock
Product: Performer RPM Ford 351C
Material: Aluminum
Head Fitment: Ford 351C, 351M, and 400M
Port Job: 61629 Complete
Combustion Chamber Shape: Compact charge
Combustion Chamber Volume (cc): 60
Intake Runner Volume (cc): 190
Exhaust Runner Volume (cc): 90 cc
Intake Flow at 0.600 Lift With 28 Inches of Vacuum: 260 cfm
Other Applications: Chevy, Ford, Dodge, AMC, Olds, and Pontiac

For more information, contact:
Edelbrock Corp. (Headquarters)
(310) 781-2222
www.edelbrock.com

Ford Racing
Product: Small-block Ford Windsor
Material: 356-T6 Aluminum
Head Fitment: 289/302/351 W
Port Job: As Cast
Combustion Chamber Shape: D
Combustion Chamber Volume (cc): 351 W
Intake Runner Volume (cc): 160
Exhaust Runner Volume (cc): 53
Intake Flow at 0.600 Lift with 28 Inches of Vacuum: 220 cfm
Other Applications: Ford

For more information, contact:
Ford Racing Parts
(586) 468-1356
www.fordracingparts.com

Holley
Product: H-151
Material: Aluminum
Port Job: As Cast
Head Fitment: Big-block Chevy
Combustion Chamber Shape: Kidney bean
Combustion Chamber Volume (cc): 110
Intake Runner Volume (cc): 261
Exhaust Runner Volume (cc): 123
Intake Flow at 0.700 Lift With 28 Inches of Vacuum: 301 cfm
Other Applications: Small-block Chevy, small-block Ford

For more information, contact:
Holley Performance Products
(800) 246-5539
www.holley.com

Hot Heads
Product: Hot Heads
Material: Aluminum
Head Fitment: 331/354/392 Hemi
Port Job: As Cast/Race Port
Combustion Chamber Shape: Hemi
Combustion Chamber Volume (cc): 100
Intake Runner Volume (cc): Based off of the 331
Exhaust Runner Volume (cc): Based off of the 331
Intake Flow at 0.600 Lift With 28 Inches of Vacuum: 274/367
Other Applications: None

For more information, contact:
Hot Heads Research and Racing Inc.
(336) 352-4866
www.hothemiheads.com

Merlin
Product: Merlin X
Material: Aluminum
Head Fitment: Big-block Chevy
Port Job: Raw
Combustion Chamber Shape: Heart
Combustion Chamber Volume (cc): 80
Intake Runner Volume (cc): 345
Exhaust Runner Volume (cc): Unknown
Intake Flow at 0.700 Lift With 28 Inches of Vacuum: 400 cfm
Other Applications: Small-block, small-block Ford

For more information, contact:
World Castings
(810) 939-9628
www.worldcastings.com

RHS
Product: Big-block Chevy
Material: Cast-Iron or Aluminum
Head Fitment: All Mark IV and V Blocks
Port Job: Rectangular
Combustion Chamber Shape: Open Chamber
Combustion Chamber Volume (cc): 119
Intake Runner Volume (cc): 320 and 360
Exhaust Runner Volume: Unknown
Intake Flow at 0.600 Lift With 28 Inches of Vacuum: 360 cfm
Other Applications: Small-block, small-block Ford

For more information, contact:
Racing Head Service (RHS)
(877) 776-4323
www.racingheadservice.com

All Pro
Product: Hurricane LS1/LS6 Cylinder Heads
Material: Aluminum
Head Fitment: GM LS1 or LS6
Port Job: As Cast
Combustion Chamber Shape: Heart
Combustion Chamber Volume (cc): 64/72 cc
Intake Runner Volume (cc): 230
Exhaust Runner Volume (cc): 88
Intake Flow at 0.600 Lift with 28 Inches of Vacuum: 295 cfm
Other Applications: Small-block GM

For more information, contact:
All Pro Aluminum Cylinder Heads Inc.
(740) 967-7761
www.allproheads.com

Custom Porting and Profiling

CNC Cylinder Heads Inc.
(727) 527-8866
www.cncheads.com

Direct Motion CNC Cylinder Heads and Porting Service
(909) 597-4919
www.directmotion.com

M2 Race Systems
(732) 751-1902
www.m2race.com