No spark plug gap?

[tweakado]

Or a piece of vac hose to feel it go in and start threading in then a socket to tighten it.

 

[89Daytona]

You could just start it up without those plugs in and see if anything comes out the sparkplug holes. Don't look right into the hole if you do this, you can get stuff blown into your eyes/face.

 

[RichP]

One plug at a time, install one plug, turn engine over by hand two complete revolutions and remove plug. Do each one one by one. This just sounds so weird to me...