Thanks to this post and the video above, I decided to finally block my AIS. I as not able to locate a thin walled vacuum cap the correct size at any of my local parts stores. I headed to Lowes to look for some aluminum round bar to cut down a block it that way. While walking down the isle, I just happened to notice the protective thread caps.
These come in 1/2" but aren't quite as long as I would have liked and a bit thicker than a vinyl vacuum cap. To be on the safe side, I went and looked for 1/2 round bar as well. They had none so I got a short piece of 1/2" allthread. My thinking was to cut it down, dremel a screwdriver slot in one end and screw it down in the hose to where I could still put the hose back on the bottom of the air box.
When I got home, I attempted the cap and it wouldn't go on but was close. I used the end of a craftsman 3/8ths ratchet and shoved the cap over the end. That stretched it just enough and I was able to get it on the air box. Just a squirt of wd40 on the cap and the hose easily went over the cap. As I said earlier, the cap is a little thicker, so the clamp would not go over the hose. I ended up using two zip ties to secure the hose on the bottom of the air box.
It feels solid so I think it's good to go.