Quoted from Skybug:Thank you! My three machines vary from 2° to 4°, if I am reading the clinometer app correctly. Looking forward to faster games!
Gottlieb's tend to suggest a 3.4°-3.8° angle.
With old EM's that have severely cupped inserts (most Williams EM's) a low angle may lead to the ball getting stuck in cupped inserts. A higher angle will alleviate this issue.
Table angle is a matter of preference. As the angle changes so does the ball behavior on the table. This may lead to ball draining less or possibly more, experiment with it.
With a paly field that is in good shape and minimal insert cupping, you don't need a high angle for snappy game play. If a game is using 24VAC on the pops and flippers it will not play as fast as a 24VDC set up found in later EM's on the same flat surface. And I'm not suggesting people hack the EM's to 24VDC pops either. I like to leave the games as originally designed.
I recently picked up a Gridiron and at some point someone installed a 24VDC rectifier on the pops. The pop bumpers had never had the spoons cleaned and still has the original and dirty metal coil sleeve. The inserts all had some slight cupping typical of Gottlieb's. And to top it off the playfield was about as dirty as they come and never been cleaned either.
My point is, they tried to improve ball speed rather than simply doing the basic maintenance. The flatter and smoother the table, the faster the ball speed will be.
Personally, I don't like an EM over 4°.