I've decided to stick with the 307 in my 87 Fleetwood for now being that it runs good and go with a 403 later on. Anyway the car needs an exhaust so I'm going to install a dual exhaust on it. Think I'll see an increase in power by doing so?. I'm thinking 2.25" exhaust would be fine. I wont be running cats on it since there are no emissions laws in FL. Also I'm thinking about removing the smog pump, any reason not to?. Thanks.