You don't need no fancy machine....
see:
http://speedtalk.com/forum/viewtopic.php?p=207546Here is the pic of what I built:
http://i171.photobucket.com/albums/u286/1fastmopar/DSCN0234Large.jpgI don't have an pics at work, but it works well...
I used an innovative motorsports LM-3 to record the spark timing and I could create a 3D plot of the curve as a function of RPM and vacuum
You could also just use a timing light... Plus you can fire all the plugs which is cool as well...
and it is also a chair...