Call Todd at TC diesel and he will set you up. He mods the inlets and outlets as well as ports the rail
You pushed a cat through your fuel filter? That's one hell of a lift pump! jk! I had Todd do my rail just to increase volume. I don't have any before and after dyno comparisons to show any difference and can't tell a difference from my SOP dyno.I don't see any reason to port the rail or to go to larger connector tubes. It makes sense in theory but I have not seen anyone notice any real world gains. Trucks are running 750-1000hp with stock tubes and rails so I don't see the need. JMO.
Heck my 750 was with a cat and going thru the factory fuel filter, which are parts most people say are a must to remove to make power. But what do I know.