Track tested. Dyno proven.
We recently updated our LS3 head porting program for a larger 281cc intake port volume – the same cylinder heads on GPI’s Ryan Steven’s record-setting 5th Gen Camaro during his 9.25 pass!
Our 281CC LS3 / L92 / L99 / LSA head was developed specifically for the stock displacement LS engine to deliver improved cylinder fill in the lower RPM ranges while adding substantial airflow increase in the upper Ranges as well. Our testing has shown over 30 hp increase while improving torque below the curve.
GPI has a long reputation for setting records at the track. Track results never lie!
OEM Casting ported and chambered – with valves less springs. Note: The below results are from our previous 268cc cylinder heads, awaiting dyno results of the new 281cc program!
Intake Port Volume: 281cc
Exhaust Port Volume: 98cc
Lift | Intake Flow @ 28″ | Exhaust Flow @ 28″ w/ No Pipe | |
.300 | 223 | 147 | |
.400 | 276 | 185 | |
.500 | 317 | 211 | |
.600 | 339 | 230 | |
.700 | 354 | 242 | |
.800 | 356 | 250 |
Turned Out Fantastic!
only 3 week turn around! They turned out flawless!
Great quality machine work and assembly! Made 478whp/425tq @3200ft altitude on my heads/cam/intake C6 LS3.
👌🏽
Heads look brand new