where do u think is my best bet to get a stock N75 valve ? dealer?
 

I have an overboost problem that I think the N75 valve could be causing... if its not the N75 valve is it a possibility that the Neuspeed software that i am running could be causing it. The problem starts at about 3700 rpms and my boost spikes till there is fuel cut about 27 psi and then the boost falls to about 5 psi which i belive would be the car putting itself into limp mode because of the overboost. before i send out my ECU for re-programming i need to try a new N75 and see if that is the problem. Anyone have an extra new N75 or know where i can get one without getting raped by the dealer price?

Sounds like...>
 

You have an uncontrolled boost situation. As N75's rarely go bad, but hoses do, I'd check the hose from the side of the N75 to the wastegate. A bad or leaking hose there (several here have had this failure) will do exactly as you describe. It's not the software BTW...

Also, when an N75 stops working, you'll get 5PSI....Unplug it and see...

it sounds more like a MAF issue...at one point, i couldn't control my boost spikes..
 

was pegging the gauge past 27psi and going into limp mode. cleaned the MAF and it would be fine for awhile, but come back to haunt me later. i finally changed my OEM out after almost 5 years.

a dirty MAF can cause misreadings, etc...giving you the spikes.