Has anyone ever rebuilt their motor and converted to a normally aspirated setup?


I wonder how much weight you could lose by replacing the supercharger and removing the associated cooling systems.

Probably a bunch. Here's some components you could lose and some guesstimates of their weights:

Supercharger: 30lbs
SC Cooling Tank: 3lbs
SC Hoses & tubing: 8lbs
SC Coolant: 14lbs
SC Radiator: 10lbs
SC Coolant Pump: 12lbs
 
To make 650 with one of these motors will take at least 110 octane fuel, John from accufab has made good power and roush just did a motor that made 640with some 620'' lift cams. It could be done though. I would think that it'll take 13 to 1 plus compression to make over 650 na hp. E85 would be the fuel of choice to do this for sure!!