I forgot...take the throttle body (?) off the truck when you do this. That restrictor is held in by a couple of small screws, (I've seen rivets, too) & you don't want those falling down inside. Ive seen some guys put a couple of 'loc-tight'ed screws in those holes. I epoxied the holes on mine, but, that kind of freaks me out a bit, so I end up checking it all the time. I'll put some screws in there when I feel like taking everything apart, again. I was told that leaving the holes open will effect the idle. I never left mine unplugged so I don't know if that's true or not. Don't waste your money on the so called 'Hi-tech' aftermarket blades. They're the same as the stock one in there now, just without the little holes in them. Thinner plates or 'knife-edged' ones that are advertised are not going to give you any real performance boost.