These models fit 265-400 Chevy engines with standard 23? heads. The units have primarily designed for oval track racing with sealed nozzles for protection on dirt tracks. Ram tubes not included. 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.