Or you could clean and and media blast the intake that in on it. It may only be a 2bbl intake but it is alum. Then buy a 4bbl air cleaner and cut the center out of the factory air cleaner base and weld it to the 4bbl air cleaner base. As far as exhaust you can use any exhaust for any gbody olds v-8. Headers included. Be careful on vavle cover choice some may not work. I don't know this for sure but a search on the 2 parts sites (Summit/Jegs) for 260 olds valve covers comes up with 1. Face it a 4bbl carb will not add much if any performance to the little motor. So it's better to keep whats there and Keep the harmony and driveabilty in the car and not have to deal with tunning headaches putting a 4bbl carb on a 260 would give. You will Need a very small 4bbl. as in like a 390 cfm. Nuch bigger and you start hitting the bogging down nightmare. Hell mine when it's cold bogs with the 2bbl. I actually was considering the same things as you with leaving the 260 in for a while and enjoy the decent gas milage and smooth running. I have already gutted everything not needed from under the hood with intails pretty much all the emission equipment, air pump and tubing was the first to go with the a/c with didn't work anyway. Then I cleaned the wiring and vacum lines up and got rid of what wasn't needed. Engine compartment is pretty bare now. The only thing that was an option the stayed was the cruise control since it actually still works. And when I build my engine (sbc) I will find a way to adapt it to it. If you have a questions or need pics let me know.h