I think that most of Fender tube-combos sound really close to that with any decent hi-gain pedal, or with a combination of overdrive boost and amp distortion. I've ended up in way too many situations in my music school, when I've had to play metal through these kind of amps on rehearsal or a gig. The pedal is probably useful, but I'm pretty sure that the major part of that sound is the twangy bounciness of Stratocaster played through Fender amp.
Actually, that sound reminds me of how Devin described the guitars on his upcoming album. Beware, ZZ-Top-CCR-metal is on it's way!