Ebay Spark Plug Wrench and Socket
seriously a lot...........
of plug & wire changes. Normally while doing headers or heads, and have never used one. I have had one available, but can't see where it would be helpful. It actually looks like it would make the job harder. 
You need a stuby flex head wratchet and several different size extentions. A regular spark plug socket and a flex head one helps.
stubby version on sale at Sears that is OK once the plug is
freed up. A plug socket, universal joint and 3/8 ratchet
gave me the freedom I needed for that. A swivel head
would be nice, that's one I don't have. The u-joint is kind
of the same thing only more floppy.

