shorter plug needed for clearance.

I need a shorter plug so it will fit between my top frame and the engine. Ghost0 suggested the champion L78C. I'm going to look at that one and I was wondering if anyone else had any other suggestions. I would like it to be 1/2" sorter or so. just to clarify I am talking about the top part of the plug with the ceramic on it.

I did a search but I couldn't find anything about plug length, I thought some people on here may have some experience with the shorter plugs that fit. thank you.