Did the marble mod today as my V&H Big Radius 2 into 2 pipes pop and backfire a bit. I inserted a bolt with a fairly tght fit in the reed valve tube. Popping has cut down about half what it was. I was wondering, the nut being hexagonal and still letting a little gas through whether a total seal as with a marble would improve things. Or as I have read a slight air gap like I have makes for the best result. Any thoughts on this?