I just put new 6 1/2 round speakers in the doors today. Not sure on rear yet.
4x6 are the size of the door speakers on 2004 GMC Sierra. Standard cab
The stock size of the speakers in a GMC Sierra are 4x6 in the rear. If they have not yet been switched out with an aftermarket, they will be the 4x6.
All four speakers are 4x6. I just ordered new 4x6's for my 93 GMC Sierra, and that is the stock size.
The 2003 GMC Sierra-1500 has a V6 engine.
The 2003 GMC Sierra-2500HD has a V8 engine.
The 2001 GMC Sierra has 6 1/2 inch speakers in the front as well as in the rear.
The 2003 GMC Sierra-1500 has a 4.3 L base engine size.
The 2003 GMC Sierra-2500HD has a 6.0 L base engine size.
6.5" round door speakers
The speakers in a 2006 GMC Sierra 1500 crew cab are 6.5 inches. However, the speaker manufacturer will refer to this size as 6.75 or 6 3/4 inch speakers.
What is the size of speakers on the dash of a 1991 gmc single cab
6.5