First a nitpick: gravity waves are those things you see on the surface of the ocean. You're asking about gravitational waves, which are a disturbance in the cur

First a nitpick: gravity waves are those things you see on the surface of the ocean. You're asking about gravitational waves, which are a disturbance in the curvature of spacetime. As for the speed, nobody knows! In fact for the last 100 years it was only conjectured that they travel at the same speed as light. It was only last year that a really solid measurement was taken by simultaneously observing a neutron star inspiral in both visible light and gravitational wave observatories. Presumably when you make your Grand Unified Theory you'll have to explain this.