The Weiand Stealth is a fantastic intake. It makes power like a standard Performer RPM, but it's power band is even wider.
Back in high school, a buddy ran a Weiand Stealth in a '65 with Trick Flow heads, a Comp Magnum Cam, and a bunch of other things and it screamed.
The Air Gap has larger runners than the Stealth, and unlike the Stealth the Air Gap was designed to meet the power needs up to and including a 347.
If I were you, I would just stick with the Stealth, it's similar enough of an intake, that the gain you might get from the Air Gap would be negligible at best.