Ranger-Forums - The Ultimate Ford Ranger Resource - '94 Mazda 4.0L cam position sensor

I cannot get to the bolt on my cam position sensor at the back of the engine just behind the intake manifold. I believe the size of the head is 10mm. Is this correct?
An open end wrench doesn't have space enough to move after contacting the head. It's all feel, so I don't really know if I'm getting the wrench on the head.
A box end wrench won't go on it because the sensor overhangs the bolt and it is too low to allow a regular box end wrench in there. Before I grind the box end thinner I want to be sure of the size and that I'm on the right track.
Is there a newly engineered wrench which will work under these conditions? Any help will be appreciated. Thanks, IslandFord