That may require a call to S&W for the correct answer.
I can tell you (although it probably isn't anywhere near the answer to the question you didn't ask) that most 5" 1911's will ship from where ever they come from with some where between a 16 and a 18.5 pound spring. The one exception I'm aware of is the new Gold Cup which comes with 2 springs, 12 and 16 pound.
The original recoil spring specification for the 1911 was a 16 lb spring. I'd have to doubt that S&W would deviate from decades of experience, but Joni's answer covers that.
The "Rev" does indicate some type of change, it doesn't necessarily mean in weight rating. Have you called the Performance Center to ask them?