There will be no difference to the coil.
If a diode is on the coil, then the diode could be damaged if connected backwards, then the drive transistor.

But I don't think that's what you are asking.
Running electricity through a winding of wire creates a magnetic field. That field will draw the ferrite coil plunger toward it, always. There is no way to "push" with an electro-magnet. They only pull, like all magnets. The only exception is lining up to ferrite magnets, with like poles near each other.
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Chris Hibler - CARGPB #31
http://www.Team-EM.com
http://webpages.charter.net/chibler/Pinball/index.htm
http://www.PinWiki.com - The new place for pinball repair info

Dude...I'd ask you to rethink this.
http://en.wikipedia.org/wiki/Solenoid

If you can design a coil that will PUSH a piece of ferrous metal away from it, your next job will be to develop cold nuclear fusion, and then to turn lead into gold.

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Chris Hibler - CARGPB #31
http://www.Team-EM.com
http://webpages.charter.net/chibler/Pinball/index.htm
http://www.PinWiki.com - The Place to go for Pinball Repair Info

and...think about the way that an alternator or generator works. They work because a magnetic field is placed near a coil. A pinball coil's magnetic field collapsing because the path to ground has been switched off is the same thing.
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Chris Hibler - CARGPB #31
http://www.Team-EM.com
http://webpages.charter.net/chibler/Pinball/index.htm
http://www.PinWiki.com - The Place to go for Pinball Repair Info

Exactly. That is exactly how the "Getaway: High Speed 2" supercharger and the No Fear Jump ramps work...three coils timed perfectly.
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Chris Hibler - CARGPB #31
http://www.Team-EM.com
http://webpages.chartet.net/chibler/Pinball/index.htm
http://www.PinWiki.com - The Place to go for Pinball Repair Info