stay away from x-force mate, have a search for x-force, many members on here have had issues with them, i heard the other day a whole system only costs $300 to supply and with most things you get what you pay for.
It took me 20 minutes to modify mine so it fit perfect - just had to re-do the rear hangers in the end.
Like I said before, the 3" xforce on my friends ssv fit perfect and sounds great.