You don't need no fancy machine....

see: http://speedtalk.com/forum/viewtopic.php?p=207546

Here is the pic of what I built: http://i171.photobucket.com/albums/u286/1fastmopar/DSCN0234Large.jpg

I 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...