No problem, it was alot easier to cut, didn't keep the stock setup anyways. Self install time for me was about 2 hours, the hardest part was getting the rubber hangers off and on the supports.
As far as the K&N/Borla combo, they work well together with the V8. With just normal driving conditons you can hear the Borla rumble on acceleration. When you get on it you have a combination of the Borla and the whistle of the K&N through the gears till you level off, buddies of mine say that it sounds like a Mustang. I've driven behind it and it's got that throaty rumble but not annoying like some others.
I can definitely feel more horses pumping through. Also it feels as though there is a better response with the throttle, not that hesitation anymore. Can't beat the look of the dual setup either.
Performance wise, I did not see a loss in MPG until I went up a size in tire. Lost about 1 MPG.
My time frame for install:
Borla - 5/05
K&N - 4/06
265/70/17 - 4/07
Hope this helps.