The IRS in the photos is a reproduction handmade by Martin. When the car was sold off the Ford Corporate lot in 1973-74 for $3,000, the IRS was missing, as was the fuel injection. Martin made this repro IRS from a drawing that Fred made for him.
You CAN NOT slide out of control with this IRS, at 500hp into a corner (that's why I can't see why SVT can't make one for the new Shelby). Martin punched it many times into a corner, and could not do a power slide with the IRS. He had to use a 351 Clev. driveshaft cut into pieces to make the half-shafts, since the first set broke!!
Martin, with me, contacted Fred Goodell, and guess what? He had the Conelec Fuel Injection in his garage all this time!! So--it went onto the car!
Hmmm...looks like I need to include this story into the new Registry book!
Paul N.