I hope that this rumor is true.
If so, I'm still not sure exactly why DC delayed the announcement because the timing of releasing the new Viper Coupe AND 625HP would have been MUCH better than releasing the new Coupe without any mechanical changes, and having the Z06 get a strong leg up publically.
Shaving weight is indeed a great way to make the Viper more competitive, but GM likely spent a LOT of research, development, and tooling money to lighten the Z06. And DC is NOT allowing anywhere near that kind of budget for the Viper.
The $300K Lamborghini Murcielago weighs about 200lbs+ more than the Viper coupe, the Veyron weighs 700lbs more, and the SL65 weighs over 1000lbs+ more! But most people don't classify those cars by their weight, but by their performance.
The Ferrari Enzo and Porsche CGT are both about 200lbs lighter than the Viper and employ $$$ carbon fiber chassis/tubs to hit that weight, but it's the 651/605HP that gave them most of their performance edge (for a steep price) over their competition.
625HP, Motons, Quaife, switchable TC (and a real rollbar on the convertible Viper) would be all that is needed to raise the Viper up to being with the top 1% of performance cars again. And DC
could easily produce such a Viper for under $100K if they put their minds to the task.
Being lighter would be a big plus, but I wouldn't trade ONE of the above-mentioned factory mods (especially power) for weight savings (while importantly keeping the price under $100K).
I just truly hope that this isn't another empty rumor, and that DC formally announces the performance improvements soon!