Gentlemen,

Hoping for advice for a good (reasonably priced) compression tester. I could not get my old Craftsman unit to thread into my 86 Explorer 302 heads. So I ordered a "Performance Tool" unit with the same result. Looks like the tester fitting needs to be more tapered/deeper to start in the spark plug hole.

I even tried to grind more of a taper on one fitting in hopes that it would then start. My heads are the GTP version, but I don't think the plug holes would be any different that any other small block. Spark plugs start super easy,

Is this just me ???? Has anyone else ran into this ??

 

The GTP heads use a longer threaded spark plug than all the other small block Ford heads (except the E6SE heads which use the same plug) That's your problem.

 

Baddad457,

Thanks for your reply. Glad to know it is not just me!

I must say that these GTP heads seem to make darned good power, but between having to pick exhaust headers carefully, and now having to struggle with compression testers and maybe leak down testers I am not so sure that I would go this route again. Would probably just go with GT-40 heads and leave it at that. Thanks!

 

Just break up an old spark plug and weld or braze a fitting to it that fits the tester.