273 warm up!

I have a 1965 273 2bbl standard bore and compression with original heads/rebuilt.
I recently acquired a factory 4bbl intake, casting number 2465726. My goal is to get better performance without swapping motors. I was planning on adding a cam and headers and probably better ignition. I know there was a commando 273 with 275 hp. what are the differences between that motor and mine? Besides my planned changes, would the only thing I need to do, is to change pistons for a compression boost? I was told this is THE place to go for small block MOPAR advice. Any suggestions on specific carbs and cams and ignition systems etc. would be appreciated. If you can't tell, I am trying to keep this a low budget hop-up.