The L98 Corvette heads are the Pre-Vortec HP SB 350 Heads . They were used on 1986 to 1991 L98 TPI 350 Corvette and on 350 HO ZZ3 AND ZZ4 crate engines . Casting # 14101128 was on the 1986 to 1987 and had the heat riser passage . The Casting #10088113 is the 1988 to 1991 heads . Both castings are 58CC chambers 1.94in/1.50ex valves with angel plugs and 163 intake port volume . They are made out of Aluminum and make 345 hp when on the ZZ3 350 HO . With some porting they can be made to make more power . COOL
