By the way, there are two important processes that should be considered with
aluminum heads and steel spark plug threads.
1. the different rate and extent of thermal expansion
:heating and cooling might break the corrosion bond

2. electrolysis between dissimilar metals causes corrosion between the
surfaces.
: there are compounds that should be applied to the plug threads to reduce
the effects of electrolysis.

Henry

"Henry" > wrote in message
.. .
>I agree, head removal is the propper way.
> I ran into this before with an aluminium head, its just not worth it to
> drill the core with head in place.
> If all the ducks are lined up (parts, tools etc) its an easy job.
>
> Henry
>
>
> "Tokay" > wrote in message
> ups.com...
>> If getting stuff in the cylinder is a big fear, why not take the head
>> off? You lose a little bit of leverage that way, but at least you
>> could get at it from both sides.....
>>
>>
>> Just an idea, I'm no expert.
>>
>
>