Starting a thread on what is best for the 4.0. And the jeep it self. So we can all learn what works the best. For example make sure you replace your spark plugs with champions. When you change out your valve cover gasket make sure to get the rubber gasket instead of the cork one. Have a strong arm and 3/4 or whatever size lugs you have. because the stock one will break.

 

i try to file mine before 4/1

 

If you've got an 87 to 90 Renix Jeep, click on the link in my signature. An index of the tips is in Post #1. Posts 1 through 5 are things you just need to do as a matter of course and they cost nothing but a little time.