[rlane]

John...YES!
The first time was painful. I presume your SC still has AC in place..and possibly air pump? (If air pump..get rid of it! IF A/C unbolt from support bracket and hang over side of fender with a towel under it..do not unhook hoses!...this will save you many scrapped knuckles. You may also want to remove the 3-4" ventilation hoses on the left side.
Then use the spark plug wrench from the cars tool set. I realize it is not chromed and pretty but you will find that it works as well as any tool on the market short of the Hazlet special tool. I found that a short Craftsman 3/8 w/flexible head and a 6" extension will get the job done. The tool set spark plug wrench is normally turned by an allen wrench.?10mm...at least on my 78SC.
It will get much easier each time you do it, takes maybe a half hour now on my 78...much less on my 73 w/carbs..ther is a wide open view of each spark plug in that engine bay.
Good luck...have a brew!