1973 Duster slant 6 performance

Hi, I'm new to the forum so bare with me. I recently bought a 73 duster and spent the last few week when I'm not at work getting it to run better and fixed the little rust on it. However it is only a 198 and I would like to get some more power out of it. I don't need anything crazy because I'm not going to be racing it or anything. What would be the first parts you would upgrade/install? Thanks for everything anything should help!
Author: 73duster