Who's running NGK ZFR5N in there Slant?

Put the NGK's ZFR5N's in today. Love the extended tip, and motor runs great. I did not like that the base of the plug was smaller in diameter. I tightened them and they got kind of tight and then went in a couple more turns to finally tighten properly. I wonder if they pushed through the end of the tube a little because they are more narrow? Engine idles a little better