So, I picked up a "spare" Fluval 404 main head section for $5. Brand new. Cant go wrong at that price I figure.
Get home... damn thing has different clamps on it that the one I have at home. I found that to be strange. Ticked me off a little bit too. But, I think that the clamping handles can be swapped over.
After looking a little bit, I think they also changed the impeller design along the way. I hope that wont be another surprise.