One good way to get a 305 to outperform a 350 is to supercharge it.
Needs air flow too. (DIY porting really helps)
a 142 blower is very very effective on a low compression 305.
A low compression ratio is one of the keys. ( (70++cc) large chamber 350 heads *1.94x 1.50 valves on a dished piston 305)
high perf engines make more power by increased air flow. Not by increased $$$ flow.