Spark Plug confusion

[Peg8687]

I pulled Autolite 764s out of my GT-40P heads. But i went to the parts store and they searched for 98 explorer it showed the 764s and then NKGs R-55s i think....so i went with the NGKs. The Autolites looked like the bottom right picture, and NGKs like the bottom left.....Now my car has a horriable miss....

Which plugs do i need with GT-40P Heads and what size Gap.

THank!!

 

[Mustang5L5]

For GT-40P heads you still would use an Autolite 764 (or Motorcraft SP-447 which is the preferred plug)


Gap is 0.054"

 

[Peg8687]

with the ends that look like the one on the bottom right?

 

[Mustang5L5]

Nope

I have one here and it looks like this

http://www.skidim.com/prodinfo.asp?number=RP030007