i've got a friend with a 2010 silverado. he needed a new pcm, and got one used from a junk yard, the part number is exactly the same. but its for a 2 wheel drive avalanche with a 5.3, his is a 6.0 4x4. Can i read his current pcm and do a write entire to the new one? will that do the whole OS? and i would only need credits for the new pcm right? i'm sure this has been asked before but i couldn't find it. thanx