what spark plugs recommended for gt-40's?

[wildstang89]

Whats a good spark plug to use for a gt-40 head(not p's)? I bought some motorcraft 42's and for some reason they won't thread into the head. It had autolite 765's in it when I picked the heads up. Any help?

[Metcalf Racing]

Nope go buy some plugs for a 93 cobra. The threads are different

[93snake]

765 is a bit hotter, think its is 764's in autolite, but I used 447 motorcraft in my cobra before, now I run nkg 3403 platinum. Hope that helps

[Jeff88coupe]

Autolite 764 or 104's are 1 step colder...good for n/a use. Can even get them at most walmarts.

[wildstang89]

Thanks for the help guys! I thought I was losing it when they didn't thread in. lol
Never ran gt-40's before. Now I know! Thanks again! Steve:bigthumb

[wildstang89]

Any idea on plug gap? Same as stock? Thanks

[Metcalf Racing]

If your running na I gap around 55 if its injected if not 45. But to each their own

[wildstang89]

Thanks! I'll try 55 then.