I kinda doubt the LT1 was faster than your LS1. By lid we mean the part right above the air filter. The stock lid is full of baffles that prohibit airflow. It's a great first mod to do. Personally I'de recommend a Texas Speed lid. I've never heard of anthing from BBK. There are couple aftermarket intakes you can buy, but unless you're going big cubes or extreme heads/cam combinations, I'de stick with a regular LS6 intake. As for removing your cats, I'de have no idea. I have custom true duals that were fabbed without cats. Most headers come with Y-pipes without cats, so that would probably be the best choice for that.