We couldn’t find much on the Challenger special, but the guys at Mustang Attitude have a nice write up so definitely check that out here. We took a small quote from their site below:
The Mustang Challenger Special was a Mississippi special, but this was quite different from most specials of the era. The Challenger Special was a dealer modified Seafoam Green car with hardtop coupe bodystyle and powered by either the 289 cubic inch V8 with 4 speed manual or 302 cubic inch V8 with 3 speed manual. The cars got Shelby intakes and a special 4118 Holley carburetor. In order to keep the cars as light as possible, things like power steering, power brakes and air-conditioning were removed. The Challenger Special was aimed at affordable performance improvements. It added more power and improved performance through weight reduction and it made a big difference. Some claim “Shelby-like” performance but we suspect that it was some way off those numbers in the real world. In terms of production numbers, it is estimated that there are 21 units with a 302 V8 and a handful with the 289 V8.