Need a y-pipe for a stock 318.

I have most of the exhaust on the car. It was already split into duals from the slant manifold. I am gonna run it into a y-pipe from the stock manifolds and then break off into duals. I didnt know how it would sound with each manifold having a set of pipes without having an x-pipe or h-pipe in it. So i figured I would just do it this way unless someone convinces me otherwise. Im new to mopars so i dont know the best way to do things.