Depends on the year. I have a 1993 Dakota, and any Dakota from 1987-1996 should be the same... In my Dakota the front speakers are 5 1/4" and the rear are 5"x7"
What Size Speakers Are In A Dodge Dakota?
I have a 2000 dakota with the regular cab. The front speakers (on the doors) are 6.5" the rear speakers are the same according to Best Buy's computer system