It was the lower intake gasket. 2004's will have the updated gasket. I don't know how well it really works. Mine hasn't started leaking again after 18,000 miles. But it took almost 60,000 for it to show up the first time. Anyway, you should be alright. Just keep your eye on your oil, coolant, and look for stains on the block.
The GAGT 3400 is pretty sweet. It's the same motor as the Aleros, but with a different trans cal and higher final drive, making it a little quicker. Head over to
www.grandamgt.com for more info.