Spark Plug Gap

Spark Plug Gap 4.0L 1.32-1.42 mm (0.052-0.056 inch)
Spark Plug Gap 4.6L Early Build Black Coil Boot 1.15 +/- 0.13 mm (0.040-0.050 inch)
Spark Plug Gap not adjustable
Spark Plug Gap 4.6L Late Build Brown Coil Boot 1.05 +/- 0.05 mm (0.039-0.043 inch)
Spark plug gap 5.4L 1.04-1.20 mm (0.041-0.047 in)