1974 318 duster. Can I port/polish these heads and get enough power out of them?

When It comes to low powered (low cr "compression ratio" /2bbl) engines there's usually a decent amount of power improvement with a a few basic mods eg 4bbl, mild cam, headers/exhaust and tune. Basically this 318 Long Block Bolt Ons - Tech Articles - Mopar Muscle Magazine 282hp @ 5000 rpm, what I consider easily attainable and fairly cheap above this hp becomes harder and more costly per hp. This engine is about 20 hp shy of your goal, cheapest option would be change goal to 282hp, another way would be a bigger cam but will be less streetable even with decent cr and with low cr not the best way to go. So leaves either better flowing heads and or more cr, a bump up to 9:1 cr would probably get ya there with no porting. Above cam/headers/4bbl most 318 guys have to decide if they want to invest $$$$ in better heads piston etc.. for 318 or go the 360 route, either way even with your low goals I'd rather have either LA or magnum 360 ported or not over ported 318 heads and go 9:1 cr 4bbl headers xe262h or even xe268h or similar on either bottom end. But if your looking for bang for your dollar a running 5.9l magnum makes 300 hp with just 4bbl add mild cam and headers for 350hp ish, I imagine 5.2l would be similar and or not too far behind.