Front Left and Right Door 6.5inch
Middle Passenger Left and Right 6.5inch
I do believe all is correct from numerous sources
for sure the rear because I just replaced mine in my Tahoe!!
All sizes are correct, there are also some tweeters (do not know size) in the front of the armrest on the front doors
Good luck finding a GOOD 4x10 (and no a 6x9 won't fit there is not enough room behind) I found some descent Pioneer 4x10's at Wal Mart a few years back. At the time they were the only ones I could find with ANY brand name on them.
also infinity makes a two way 4x10 speaker that works with a little crafty engineering.