Mechanical Lifters

My guess is youre rocker arms have slot pit screw rockers, You will also need a wrench and feeler gauge, I am not sure what the spec are on the feeler gauge, Best to get or look into the haynes repair manual, First with the valve cover off, (Youre gonna need another one). Also with the wrench youre gonna need to undo the nut W/ slot (flat head screw driver) To undo the nut. Then add the feeler gauge to the right measurements, Then place them in between the rocker roller arm & the cyl spring seat, Then tighen the slot pit screw, This is the important part, Now u want to have the slot pit screw only tight enough, So that the feeler gauge can roll out easily through the rocker roller, Once its at the correct tightness, With youre wrench tightn the nut up, Also recheck the rocker roller, Again to see if its still correct, If so continue onw with the others in the same way.

Good Luck.