what is the differance?

Ok, this may seem dumb but what is the difference between the standard LA small block and a Magnum motor? I have a crate 360 in my 67. Runs like a top. But the valve covers are different the intake is different. What's inside that's different? I've had my old 69 340 apart so I know what's inside of that, but what's different in this 360?(cars runs great and only has about 2000 miles on it. No need to tear into it yet)