These are the Ford stick style Injectors used for the popular swap. They spray from 4 holes VS 1 of the OEM injectors. Which means Better air/fuel mixture and better fuel atomization. On my jeep it Improved the running condition returns to idle faster and performes smoother. They are a direct plug in and worth the effort to swap Even a stock 4.0 Will benefit. Before you order i need to know what style plug you have. Also i can send the Round style Connectors for a few bucks more if you want to Re-pin the harness. I have a few extra sets (6) in great working condition. 45$ shipped in the 48 states.....