a 305 is a good motor. But---it will never give you the performance of a 350. There is no substitute for cubic inches. Best advice---buy it, drive it, see what you are happy and/or unhappy with. If you feel the need for more power, buy a 350 from the junkyard and rebuild it, or buy a 350 crate motor. Too many hotrods have died a lingering death because people pulled out the "every-day" motor to rebuild it or 'soup it up". and then got stalled. The vehicle is then undriveable, never sees the light of day again, and is sold off as a basket case to get rid of it.