8 3/4 price

Im working on a 73 dart with the 8 3/4 and it has lbp and its 100% factory. my 68 formula s has sbp
I'll believe that when I see it.....maybe not even then! I've dealt with 100's of those cars and have never seen one from the factory. If they made them, where are the rest? They wouldn't have made just one or even a dozen. They would have made a run of hundreds at a time and had them in the parts book. I've looked in the factory book, they're not listed. Now if it was a prototype or one-off promo car.....who knows what they may have made but it would probably be unique. Do you have a build sheet? Fender tag we can chew on?
Thanks, Mark