2.9 1990 Ranger Spark Plug Wire Issue

Would like to know some pointers for getting the spark plug wire to stay on the number 3 cylinder? I had the problem a few years back and then passed the truck on to my dad who has it now. We usually just push it on as far it goes but you can never hear or feel that click and as you guys know that 3 plug is in a PITA spot. Reason I ask is I'll be changing the plugs out this week and would like to keep it on for good.