On my 2007 Tacoma Access Cab they are 6-1/2" round speakers
This site has lots of links with stereo help for your tacoma:
http://www.tacomatunes.com
or
http://www.tacotunes.com
Try to use Toyota speaker adapter plugs so you don't need to cut wires and mess the electric system up. You can get them from Ebay or Amazon.
http://www.customtacos.com/tech/index.php?article=303
The rear track of the 2002 Toyota Tacoma is 4 ft. 9.3 in. (57.3 in.).
The rear track of the 2003 Toyota Tacoma is 4 ft. 9.3 in. (57.3 in.).
The rear track of the 2010 Toyota Tacoma is 5 ft. 1 in. (61 in.).
The rear track of the 2011 Toyota Tacoma is 5 ft. 1 in. (61 in.).
The rear track of the 2013 Toyota Tacoma is 5 ft. 1 in. (61 in.).
The rear track of the 2009 Toyota Tacoma is 5 ft. 1 in. (61 in.).
The rear track of the 2014 Toyota Tacoma is 5 ft. 1 in. (61 in.).
The rear track of the 2006 Toyota Tacoma is 5 ft. 1 in. (61 in.).
The rear track of the 2008 Toyota Tacoma is 5 ft. 1 in. (61 in.).
The rear track of the 2007 Toyota Tacoma is 5 ft. 1 in. (61 in.).
The rear track of the 2012 Toyota Tacoma is 5 ft. 1 in. (61 in.).