Another thing to consider when adding the 69 mustang headrests to your stock EB seats. On the passenger side, because of the increased height with the 69 headrest, the seat likely won’t clear the dash to tumble forward. It will still fold forward but won’t tumble for back seat access. A guy on here, BigJHoov, makes brackets that allow you to move both the passenger and driver side seats rearward but still mount in the factory seat bolt locations. (Side note: If you’re a taller person, IMO, moving the stock EB driver seat back is a must ) After I added the 69 mustang headrests to my factory EB seats, I was able to clear the dash to tumble my passenger seat when I used the most rearward position mounting holes on the brackets.