Spark Plug Extentions??? wtf?

[MisterMan]

Well it was time for a ture up, giving its been about 7 years, 3 years for the oil change....(I just bought this truck, i based the tune up part on what i've seen), oil change from a sticker on the window and color of the oil......

*when i removed the plugs they had a lil extention on the end hiding the eletrode up inside, not in the cylender...wouldent this cause a lesser spark, and less compression thus poor performance?....I went ahead and replaced the plugs withing the stupid housing too scared to see what was going to happen ***p.s. there was one sparkplug that was on off brand from the rest, /w/ longer threads and a larger head. The off brand was oil fouled as was 2 others.....

QUESTION: I know some stupid idiot put the wrong plug in, but y would they add an extention like that>??

Thanks for viewing,
Denny M. Visalia Ca.