For the enthusiast there's only two models that need to be considered, the SHadow ES and Sundance Duster. Equipped with Mitsubishi's 3.0 Liter V-6, and a stiffer suspension with upgraded tires, they're not the most stylish sedans available, but make very good pocket rockets.
The Duster usually came in darker colors, making it Plymouth's version of the Stealth fighter, a sneaky package that can keep up with Mustangs and Camaro's if handled correctly, all without the go-go graphics and looks that cause a policeman's hand to reflexively go for his ticketbook. P is definitely for possibilities when it comes to the P-Bodies.
Allpar's Page on The Shadow/Sundance
P-Body Enthusiast Page