I hate to break it to you, but you're all wrong.
The original showcar had 2 V-8 engines sawn apart and soldered back together to make a real V-10. The red car pictured IS that one. Then, there was VM-01 (white - I believe) also named Felicity, that was powered by a V-8 and used for suspension development. It's the one Iaccoca was pulled over in by Detroit PD when he decided to give the "GO" for Viper production. VM-02 is known as the Sedona car, it was used by Bob Lutz to take magazine writers for rides in Sedona, AZ. It was powered by a purpose-built V-10.