I have ordered new COPS and have purchased some dielectric grease. However, I am a little confused. Do I put the grease on the exterior of the boot, or the interior... both.. or just on the outside of either end of the boot?

 

Just the inside. I took a small screwdriver and smeared it around the entire length the boot then added a little extra dab in each end and reinstalled it on the COP.

 

The purpose of the grease is to 1) keep the rubber from adhering to the hot metal parts, and 2) to create a coolant-tight seal. Yes, silicone grease has a relatively high dielectric, but that characteristic isn't why it's recommended for this application. The characteristics that make it desirable are:
-heat resistance
-water resistance
-gasoline/oil/fluids resistance
-high viscosity/film strength
-sticks to rubber

Put it at the bottom of the boot inside where the boot will touch the spark plug's ceramic, and at the top outside where the fins seal against the tube in the head. You can also put it where the boot touches the coil, but it's not really necessary there.

Read this page and note that the TSB numbers linked at the R will show the full text.

 

Also, several mechanics have recommended spreading a layer over the seams on the outside of the boots. This is where the boots tend to crack or separate and it keeps the moisture out.

 

Use a little paint model brush and alcohol to clean spring ends just before install, if they get loaded up.

 

See.. I would have just squirted it into the cylinder heads and been done with it..glad I asked!

Thanks guys.