What I mean by lowering is to place spacers (washers) on the attachment screws between the carriages (front and rear) and the engine body.  I can add enough so that the driver wheels don't touch the rails.  I have backed off that extreme condition to a place where there is little "rock" fore and aft on the engine.  The gauge sounds like something I need to get and use.

I am having a terrible time getting this engine to pass through switches.  I tried to lower the rear 4 by spacers.  Also tried to do the same with the front 4.  I got to the point that the main drivers weren't making contact.  I have adjusted back to get the drivers in contact, and it still can't handle the Bachman EZ switches.  Any suggestions would be appreciated!