Can you put a 305 Chevy throttle body onto 350 engine?

No, you can't directly put a 305 Chevy throttle body onto a 350 engine without modifications. While both are small-block Chevys, the throttle body bore size and potentially the mounting flange are different. A 305 typically uses a smaller throttle body than a 350. Forcing a smaller throttle body onto a larger displacement engine will restrict airflow and negatively impact performance. You'd need an adapter or a throttle body specifically designed for the 350, or potentially one from a similar-sized engine.