I've come across a certain 1963 Plymouth Belvedere at several local car shows. The engine is apparently a 426 Wedge (it originally had a dual 4-bbl, cross-ram intake, but now has a single 4-bbl intake. Here's a photo of the car:
The owner has mentioned that he went down to the States to drag race in Super Stock for a couple years back in the mid-late '60s, so I don't have much reason to doubt his knowledge of these types of cars. He mentioned it IS NOT a 426 Max Wedge car, but rather a '63 "Lightweight". He mentioned very few were built and that the car was built by the factory (or a company Plymouth had gotten to build it). Did Plymouth build "lightweight" Belvedere drag racers in '63 with a 426 Wedge engine <span style="font-style: italic">which wasn't</span> the 426 Max Wedge?