10" brakes on formula S cars?

WOW! So much info. I'm (almost) sure they never made a Formula "S" Valiant. I'm really curious how many Hi-po 273 4-speed 2 door post V100s might have been produced. I'm 100% sure it was original as I knew the first owner and the only thing he had done to it was put a high rise intake and a holley carb on it and run the piss out of it. It was a badass on the street scene way back then. It had a 7 1/4 posi cant recall the gear ratio but I remember it lasted 10 hrs before sheared the splines on the axles. (they had been installed wrong and hadn't gone completely into the spider gears) after I pulled the rear cover and aligned the spiders, and installed a 2nd set of axles it lasted about a month and a half before I broke the spiders. At that point I knew it was time for 8 3/4,, local yard in Minot North Dakota radioed out and found 1 in Ill. or Ind. It had a 3.91 gear in it. Its gone thru a few upgrades over the years and its still my baby though it needs restored.
Sorry to bore you but two more questions b4 I get out of here. What is the fender code for hi-po 273 and what is this Hamtramack site you speak of?

Thanks Guys
Kevan