Mallory Promaster marine spark plug wires are custom pre-taylored for an exact fit. This kit is designed for big block and small block Chevrolet engines with a male HEI style distributor cap. These 8MM wires are constructed with 90 degree boots and blue silicone jacketing that repels water, oil, fuel, and withstands temperatures up to 500 degrees. The coil wire is fitted with two HEI style boots for a male HEI coil connection.