thats not a "true dual" exhaust, but its certaintly doable. wont give much power difference, definitely a different sound though.
true dual with an x pipe would be ideal, as the x pipe allows the exhaust pipes from the manifolds-back to be similar in length, but not exactly the same which saves a large headache. if you dont have an X pipe, and the separate runs are not exual in pipe length, their sound signatures will be different and it will more than likely make the engine run poorly.