This spark plug wire set is made by Ford Racing to fit the Ford 5.0L and 5.8L smallblock V8 engine. Spiral-wound construction provides the highest possible firepower without RFI (radio frequency interference). Heavy silicone insulation resists high temperatures, chemicals, and inductive cross-firing. Fits post-type distributor caps and socket-type coil towers. Spark plug ends have 45-degree boots. Blue insulation features Ford Racing imprint and cylinder numbers already marked on each wire.