They sound like this:
VROOOOOOOOOOOOOOOOOOOOOOOOMMMMMMMMMMMMMMMMMMMMMMMM M.
If its the same ones Hurricane was using back in 08 and 09, I have them on my 427 FE car and they sound awesome. But beware, the welds inside that hold the baffles in have been known to come loose and then they rattle. Don't know if anyone at SV has acknowledged that but I'd be sure and ask that they be double-checked prior to final assembly to be sure the internals are not just tacked by welded adequately.