Hekimian Racing Engines aluminum LS3 CNC ported intake, exhaust and chambers, flowing an incredible 385cfm @ .800" lift intake port, 273cc intake port, Exhaust flows 292cfm @ .800" lift, and has 120cc port, Manley stainless 2.205" intake valves and 1.610" exhaust valves, These are severe duty valves with 8mm stems, Bronze valve guides,Chrome/ Silicon Behive valve springs good to .780" cam lift, Titanium 10^ retainers, 10^ x 8mm Hard bead locks, Clad /Viton (r) valve seals, Manley hardened steel shims.
Upgrades on parts are available at an extra charge. Comes with Aluminum T&D Billet roller rocker shafts 1.7 ratio custom fit to heads
These heads are capable of making 850 HP with a good engine build Naturally Aspirated. Blown applications over 1,000 HP.