Sorry: Valve Job. That's the sign of a good cylinder head. Typically ~30% of the gains from a modern ported head come from the VJ. When you get into the 60-70% range the cost per HP ratio dips significantly and gains shrink. Of all power adders positive displacement superchargers care the least about head flow and velocity. On a 800HP car with a great port/VJ you may gain 10-15HP to the tires. Definitely not worth the money.

The full bolt-on package should belt out 770-800HP, adding a 100 shot (rated at the crank) would make for 900HP and around 175-200lb/ft of torque (extra torque due to the cooling effect nitrous has on the hot compressed air coming out of the supercharger). Since you are AWD I would assume you would break something sooner than later due to the insane torque. From my experience and that I've gleaned from others running serious HP (2000-3500HP) stick to a single power adder (FI in this case) meaning a larger supercharger head unit. Lots of custom fab work and no one to share the tab with, is the only down side.

 

Don't forget half shafts. I've heard of someone shearing one with a tuned XFR. That was at the drag strip and not running drag radials. So be careful.

 

I mentioned those in a previous post (IIRC in response to Cambo), halfshafts are easy by comparison to rebuilding a transfer case to spec.

 

I was a bit behind on the thread and responded before reading the rest of the posts

 

Absolutely no worries. Tis the season, it's 5 o'clock somewhere and I'm on my second cup of quality egg nog.