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 281cc cylinder head port program picked up additional flow while maintaining an appropriate cross sectional area, and further outperforms these results by a modest amount.

Intake Port Volume:  281cc

Exhaust Port Volume:  98cc