Most of these units are available with aluminum or magnesium castings. Magnesium units are supplied with a composite center plate as standard equipment. These units are also available for raised runner, 18? as well as other Chevy SB applications. I.D sizes available are 2- 7/16?, 2-1/2?, 2-5/8?. Fuel pump, pump drive, fuel shutoff, ram tubes, etc., must be ordered separately. Hilborn offers injectors to kit most Chevrolet, Chrysler, Ford applications including 4 & 6 cyl. (yes even Flat Heads). They also have models for VW and Turbocharged and Blower applications.