Gore/Lieberman 49% / 296 EVGingrich/Connerly 47% / 242 EV(I picked Ward Connerly, who was making the news around 2000 as an opponent of affirmative action, to run with Gingrich, just to keep it interesting. I honestly don't know who Gingrich would pick as his running mate).
Gingrich resigned from the House after the 1998 midterms, which showed unprecedented gains for the Dems after 6 years of Bill Clinton. His combative style would appeal to some, while turning off others who perhaps liked the more genial style of George W. Bush (during his 2000 campaign).
A more or less uniform swing of 1.5% to the Dems gets Gore FL and, by a hair, NH.
(Gore isn't winning Gingrich's home state of GA).