Today, dollar for dollar, is the 318 faster than the 340 ???

It's just the evolution of the same basic package, you get all the benefits of a design improved through the years....
Yes that's the same thing Ford did with the Windsor. They figured out how to make horsepower while being emissions compliant. When I think of the LA 318 I think 235 Horsepower, restrictive heads, restrictive exhaust and 2 barrel carb. The Magnum is a different thought all together, it already sounds like the heads are better for example, and that's a big step in the right direction as compared to an LA 318. yes the FI I believe runs cleaner, you dont see sludge in valve covers like a 70s carbed car.