As our stock 3.898-inch bore LS1/LS6s have become as pass as day-glow fanny packs, and many have upgraded to their iron block or Gen IV relatives, not to mention resleeved or aftermarket blocks, the aftermarket has followed suit in producing more and more heads for 4.0-inch or larger bores and big-cube strokers. In this rendition, GMHTP will attempt to keep you up to speed with the latest and greatest heads for your LS build-intended to provide enough air for even some 450-plus-cubic-inch monsters. If you're looking to dust a few Ponies or even some crotch rockets, you'd better ante up with one of these high-flowing heads. Now pair it to a well-matched cam and intake, and you're all set!
GM Performance Parts
Casting: GM L92, CNC-ported
Runners: 280/100 cc
Combustion Chambers: 68 cc
Valve Angle: 15-degrees
Valves: Stock 2.165/1.59
Valvesprings: Stock, 0.510-inch max lift
Flow: 332/201 cfm @ 0.600-inch
Options: None
Price: $580
Casting: GMPP LSX-LS7
Runners: 270/85 cc (as-cast)
Combustion Chambers: 70 cc (as-cast)
Valve Angle: 12-degrees
Valves: 2.20 (titanium)/1.61 (sodium-filled)
Valvesprings: 1.940/1.880 Beehive, 0.650-inch lift max
Flow: 303.2 @ .591-inch
Options: 6 bolts per cylinder
Price: N/A
Air Flow Research
Casting: Air Flow Research
Runners: 225/85 cc
Combustion Chambers: 62, 65, or 72 cc
Valve Angle: 15-degrees
Valves: 2.08/1.60 (stainless)
Valvesprings: 1.270 dual (0.650-inch max lift)
Flow: 320/250 cfm @ 0.600-inch
Options: Angle or flat milling
Price: $2,598
Casting: Air Flow Research
Runners: 240/87 cc
Combustion Chambers: 64 or 74 cc
Valve Angle: 15-degrees
Valves: 2.16/1.60 (stainless)
Valvesprings: 1.270 dual, 0.650-inch max lift
Flow: 345/260 cfm @ 0.600-inch
Options: Angle or flat milling
Price: $2,700
Trick Flow Specialties
Casting: Trick Flow
Runners: 225/80 cc
Combustion Chambers: 65 cc
Valve Angle: 13.5-degrees
Valves: 2.055/1.575 (stainless)
Valvesprings: 1.30 dual, 0.600-inch max lift
Flow: 338/259 cfm @ 0.600-inch
Options: 0.650-inch lift springs, top end packages, camshafts
Price: $2,400
Casting: Trick Flow
Runners: 235/80 cc
Combustion Chambers: 70 cc
Valve Angle: 13.5-degrees
Valves: 2.08/1.60 (stainless)
Valvesprings: 1.30 dual, 0.600-inch max lift
Flow: 340/270 cfm @ 0.600-inch
Options: 0.650-inch lift springs, 6 head bolt pattern
Price: $2,450
Dart Machinery
Casting: Dart, as-cast
Runners: 225/85 cc
Combustion Chambers: 62 cc
Valve Angle: 15-degrees
Valves: 2.05/1.60
Valvesprings: 1.290 Beehive
Flow: 290/205 cfm @ 0.500-inch
Options: Milling
Price: $1,772
Casting: Dart, CNC-ported
Runners: 250/94 cc
Combustion Chambers: 68 cc
Valve Angle: 15-degrees
Valves: 2.08/1.60
Valvesprings: 1.290 Beehive
Flow: 343/240 cfm @ 0.600-inch
Options: Milling, 1.295 dual valvesprings, custom order
Price: $2,700