The big dog of aftermarket Gen IV cylinder heads has arrived:  The all-new Mast Motorsports Black Label LS3 12-degree 6-bolt CNC cylinder heads.  These large bore bad boys are the only heads on the market engineered to accept LS7 valvetrain components and the LS3 intake manifold.  The heads (P/N 511-204) are designed for a 4.125"-4.200" bore so they’ll fit any GM Gen IV short block with a 4.125” bore or larger.  They utilize a 2.200” intake and 1.610” exhaust valve.  And, they’ll bolt right on to ANY 6-bolt LSX block!  Flow numbers are coming soon but the new Black Label LS3 12-degree 6-bolt CNC cylinder heads promise to dominate the Gen IV LS racing market. For more information log on to www.MastMotorsports.com or to purchase contact Mast Motorsports directly at 1-936-560-2218.