I tend to believe what Duke is saying. I had my 103 apart a few weeks ago and thought it would be a good time to screw in some new plugs. My wife was going to town and I asked her to pick up a set. She called me from the auto supply and said all they had were motorcraft. I told her to go ahead and get them.

The Bosch that I took out were opened up to about .044 or so, but even with fresh gapped plugs the idle quality got worse.

I need a set of H9DCO's and about fifteen minutes to get it right again.

Have a great day,