Quick comparison
Both appeared in 1957. Both have a V12 engine, mounted at the front. The more powerful one is the Ferrari 315 S: 360 PS versus 330 PS. The rarer one is the Ferrari 290 S: 2 units versus 3.
Both appeared in 1957. Both have a V12 engine, mounted at the front. The more powerful one is the Ferrari 315 S: 360 PS versus 330 PS. The rarer one is the Ferrari 290 S: 2 units versus 3.
All values come from the data sheets of the two models (sources listed there). The better value is highlighted in green wherever both data sheets give a comparable figure.