increase HP on a 273

Ok, so lets say i do the cam,carb,and intake, oh yeah and a decent set of headers. What is my total cost for parts? i am driving the car more and wish it had a little more push. sad to say my honda civic seems to have more power than my dart. there is a 440 on craigslist for $400 but it may need total overhaul, also there is a 383 block, heads and crank for $100. see where i am goin with this.. should stop putting money into my 273 and swap in a bigger motor?