Search my old posts on the hows and whys of using low buck 4416 305 heads on 350's
with home brewed porting and 1.94" intake valves. They respond suprisingly well to generous porting and new valves. I have build many low buck powerfull 350's using these heads. $$$These motors punch well above their weight.$$$ Of ten you can buy the whole running 305 engine w/heads for peanuts. Sometimes free. You are looking for the 4416 castings for this.
One good way to skin this cat. Do not use 2.02's in these heads. 1.94x 1.60 valves are best.