Like another member stated moving up to a coyote car with a auto trans 6r80 your gaining another 100+ HP and a great trans, as well as a nicer interior depending on the year car. Whether its a s197 coyote or a s550 its a total upgrade. I have both a blown 06GT and a blown 16 GT both auto cars. The difference in the new cars is astounding! I would not do the trans swap if I was in your shoes. Good luck to you. That low milage Bullitt should sell nicely if you sell it yourself too.