WilliamJ,

I assume you are changing the GP in a 617 engine but the 4 cylinder engines are similar. All I use are 8mm and 12mm combination wrenchs and sometimes another combination wrench to lengthen the 12mm wrench to loosen tight GP.

I found it is easier to just loosen the 8mm nut on the wire connector. Then remove the GP with the 12mm wrench. Now with the GP out of the head, remove the 8mm nut completely so the wire connector can be removed. There is much less chance of loosing the 8mm nut this way. Replace GP in reverse order.

I assume you know how to hook the box end of a second combination wrench into the open end of the first combination wrench to extend the length to give you more torque. I frequently use this trick an old mechanic showed me. Although it looks like you might break one of the wrenches, I have never broken a wrench doing it.

P E H