I believe that they are 5 1/4. Go to Crutchfield.com they will hook you up with all the sizes and specs.
4x6 are the size of the door speakers on 2004 GMC Sierra. Standard cab
6.5
6.5"
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.
6 3/4" speakers front and rear in a four door 2004 Chevy Colorado.
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.
Front speakers Front Door: 6-3/4" factory speaker note Far rear speakers Rear Pillar: 4x6" factory speaker note
what size speakers are in the 2004 Chevy Avalanche
All four speakers are 4x6. I just ordered new 4x6's for my 93 GMC Sierra, and that is the stock size.
6.5" round door speakers
crew cab door speakers are 6.5"
The 2001 GMC Sierra has 6 1/2 inch speakers in the front as well as in the rear.