I went to get a new battery for the Tribute today.
OEM model is a 40R (Motorcraft size) which no one carries except the dealer.

Upon further review, I found that other sizes are available at Kragen's and Walmart for around 45-60 dollars. You just have to measure the battery and note the orientation of the battery terminals (they are a reverse). Get the one with the highest cold cranking amps (not just cranking amps).