1989F-150

Ya i have a 1989 4.9l. I gutted the rear cat out and ran around with no muffler and its a bit to loud and burns to much gas. Plus when you get on it, it feels like it falls on its face. SO I was thinking if I cut in between the two cats and emptied the front cat then have it rewelded. While I got that done have the muffler shop put on my flo-pro. I don't know if theres different series but its the one that looks like a flowmaster. Only thing that scares me is how quiet the truck is when I just placed the muffler up there while the front cat was full but the rear one was empty. It was fairly quiet but I think if the muffler was sealed up and the front cat was gutted it would sound pretty good. All I want is a good rumble. Plus on my old exhaust systems on other vehicles I have noticed that it sounds better after the muffler warms up and the truck is under a load. Atleast I hope. I also have ethier thought about dumping it out under the truck or running a tail pipe all the way out with a echo chamber. Also is it possible that my truck well run with alittle bit more power than usual. I had a thrush glass pack on my truck which didnt do much for back pressure. I have never had the stock exhaust on it so I don't even no if it lost any power after it had a glass pack put on it. So am I in for any kind of surprise?