I put one of these in an IR3 when I was performing a light hammer (zero kick) mod. I had heard that they did not seal very well but I got it cheap so I thought I would try it out. I was very pleased with the performance. The air flow was much better than the stock valve and it sealed up great. I recommend buying one and trying it out. If it doesn't seal, you can always use the spring for the lightweight hammer mod.
Good Valve 
