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.
6.5" round door speakers
6.5 inch
5.5" speakers front and back.
6.5" speaker. That is what is in the 3.4L and there is no difference.
The 2001 Toyota Tacoma has a 2.4 L base engine size.
The 2006 Toyota Tacoma has a 2.7 L base engine size.
The 2008 Toyota Tacoma has a 2.7 L base engine size.
The 2010 Toyota Tacoma has a 2.7 L base engine size.
The 2012 Toyota Tacoma has a 2.7 L base engine size.
The 2004 Toyota Tacoma has a 2.4 L base engine size.
The 2014 Toyota Tacoma has a 2.7 L base engine size.
The 2002 Toyota Tacoma has a 2.4 L base engine size.