I think a set of headers would be a nice upgrade. You can go ultra cheap and fight low hanging headers and fight with speed bumps or you could spend the cash and get a nice set and never look back. I will give my honest opinion here: the 273 is a wonderful little engine but will likely never make an impressive amount of power without a full blown performance rebuild. I think the best thing here would be to get the 273 running tip top and enjoy it! Then if you decide you want more performance I would recommend a junk yard 5.9 magnum engine with basic bolt on upgrades. Could easily make 350-400 hp for less then $3k. The biggest thing here is to keep it running and driving! Then you won't stalk out on the project and loose interest
