#0 - Dec. 7, 2009, 7:01 a.m.
Q u o t e:
If an item has a cross-faction counterpart, it will convert accordingly after undergoing a Faction Change. For surety, you can look an item up on the Armory, and under "Item Facts," you should see "Alliance/Horde Equivalent," with a link to the item's equivalent.
As shown on the Mechano-hog's page, it will convert to Mekigneer's Chopper.
http://www.wowarmory.com/item-info.xml?i=41508