I thought they did that in the 2000+ 3100s to get that extra 10 HP out of them. Either way, after my next two commission checks come in, I'm going to get a competition ported upper and lower intake manifold from WOT-TECH. I'd like to get headers for it, too (I enjoy air flow upgrades, since they do very little to the fuel mileage), but they're hard to come by, and I'll probably end up with a set that fits the engine, but not the engine bay.