I was wondering if anyone has put a quietcore insert in their powercore IV silencer? I was wondering If it makes a big difference in the sound level? Also I need to put a spark arrestor in it and was wondering if the quietcore insert has the screen or if I need to buy it seperately and I have also seen whole quietcore endcaps for sale also. I went to the fmf website and it didn't give me a whole lotta information as far as what I needed. I would like to do it the cheapest way possible. I emailed them last week with the same question but have heard no respose so I figured asking you guys would probably be faster. Thanks for all the help.