Chuck,

From what I've read in old articles, the Spacebug has a little more performance than a Black Widow.  There was a racing carb and head that you could buy that would add about a 5-10% speed increase, depending on prop used.  I assume the head was just a high compression head like you would use on a later TeeDee.  Not sure how a different carb would work, other than just screwing a larger inlet to the venturi tube. 

These stepped cylinders are the early style.  I'm not sure exactly when Cox went away from them, but I like them.  Interestingly, since this is an early engine, the glow head of the later engines will not work on a Spacebug.  The bottom of the glow head is narrower than the later glow plugs.  Hopefully this glow head is good, as I only have one spare head with the narrower bottom.

This is an abomination in my mind.  Drilling holes in a Babe Bee tank is alright.  It only takes a couple of minutes to replace the drilled out tank with a new/used one, and old Babe Bee tanks are everywhere since people often swapped them out for the 8cc tanks.

Mark