spark plug and coil boot

[wkornf]

hey there,

I recently rebuilt my heads and threw out the spark plugs before noting the part number. so i bought some ngk tr55 as replacement. problem is they don't fit the Motorcraft coil boot, they are too loose. so I went to advance auto with coil in hand and I test fit them on Motorcraft factory replacement plugs and they are just as loose. I mean don't even make contact loose.

I'm used to the plug boot fitting tightly, is this not the case with this design??

I honestly can't remember how they fit before I tore down for rebuild.

Thanks!

 

[wkornf]

Anyone? Does the coil boot fit snuggly on the spark plug or is it normally loose?

Thanks!

 

[01yellercobra]

Do you mean the spring doesn't make contact with the plug? I don't think I've had a COP that was tight. At least not like like the old plug wire boots. How old are your COPs? You can get just replacement boots and conductor springs.