My engine is from a 79 and with all smog crap removed AND a 4 barrel carb it still only made 140 hp! So I did a cam swap! The cam is one of the first things you should probably do and then the headers. That should give you a good ooomph in the right direction. I didn't know what my hp was after I swapped the cam though because I didn't get to dyno it, but it was definetly improvement!