YJ/TJ/XJ 4.0 Top-Mount Install Guide

First of all, if you have any questions, CALL US! We will help you!

Click here to download most recent install guide.

Fuel

Be sure to run highest octane available at your pumps! This is critical for a forced-induction vehicle. If most of your tank is full of a lower octane fuel, postpone your install until you can fill up with the right stuff.

Tips to ensure best performance:

Distributor models

  1. If the existing is old, replace your cap, rotor, and spark plug wires.
  2. Use spark plugs 1 heat range colder, and gap at .029-.031
  3. Upgrade to 4-hole injectors.

Coil pack models:

  1. Use spark plugs 1 heat range colder, and gap at .029-.031