Actually, no it doesn't. To do that, you'd need to go to a flat-plane crankshaft. It just moves the point in the firing order where you find the "L L" or the "R R". 1 8 4 3 6 5 7 2 L R R L R L L R 1 8 7 3 6 5 4 2 L R L L R L R R
Heres the article, I took pics of it---(mods if this isnt legal you can delete if you choose) 1) 2) 3)
You get rid of the 5-7 next to each other, but then you have 4-2 next to each other. Just moving the intake problem to the other side. Our engine guy for The AA/GL does it this way, 7-4 swap, because he thinks it keeps 5 and 7 cooler and more even with the other s. He says on the big 582 that we run that the power is the same but he gets better temps in the head and block this way. For a 5 mile pull this is important.
On a street driven or even street/strip you won't gain or feel ANYTHING. In 17 years of stock and superstock racing it goes in and out of fashion. Some combinations it helps, some it does not. For your application all it will do is lighten your wallet. But since you asked, you need the cam, and to swap plug wires. And, it won't and does not sound different. Headers that follow the firing order to their collectors will make that indy car sound, and they have come and gone as well. But they do look cool all spaghettied all over the place.
Video of 4/7 swap. I know it's cheesey, made this when I was selling car. http://youtu.be/C70Qd_vkeKY
I know ONE GUY that does the 4/7 swap. Yes, it is worth hp on a Comp Eliminator motor that makes 900+ hp @ 10,500 rpm. I assume this is.....not you. If you do not index your plugs, have all titanium fasteners, have all ceramic bearings, have all magnesium body panels, have no water in the block, etc, you have many other places to start. But knock yourself out, whatever.
This is a popular swap with 426-based Hemi race engines... I've heard of a couple Factory Appearing/Stock Tire guys doing it. -Brad