Diablo, When you say open stack, do you mean to try it without the muffler? I cut off the restrictive tips as many have suggested and as it is now the pipes are 2 and 3/4 inches long and extend about an inch and a half below the fuse bottom. I was thinking of taking another inch off the pipes, Do you think I would gain any power by doing this? A little extra "punch out" giddy-up wouldn't upset me! I realize my muffer is more retrictive than most but I do like the fit and sound of the BCM pitts.