Ok, Bret... here is my speculation... tear on me if you want to... I am only here to offer advice.
Putting the supercharger on Brads car gave him more horsepower. Providing his transmission gear ratio was the same, for him to go faster that means his car had to run higher engine speed. If this car did not have a modified oil system, such as running a windage tray, those prolonged higher RPM's most likely caused the crank to cavitate the oil pan. This starvation of oil combined with prolonged high RPM's is probably what caused the spun bearings. No, I did not personally work with him to tear the engine apart and no I am not a master of all that is in the automobile world. I am offering my best guess, and until I see Brad's engine firsthand that is all that it is.... an educated GUESS.
As for running NOS and S/C's on a car, remember that you are doing something to make the engine run faster, which means bigger explosions, forcing pistons harder and causing rods and bearings to be stressed harder as well as doing things such as cavitating the oil pan in prolonged extreme RPM cases. The engines we buy from the factories now are designed to only run about 70% of their potential HP, but when you modify you increase and can sometimes exceed that percentage. I do not believe IMHO that you can just stick something on a car to make it work harder and expect the same life out of it that you would get while driving it stock without giving the engine internals that are capable of withstanding the increased HP. You do not see NASCAR racers taking a crate engine out of the box and sticking it in their car and then running it 8k RPM. They take a bare block and beef up everything because they know that stock parts will not stand prolonged exposure to wear and tear. Even after a race is over, they examine and rebuild everything to make sure that the engine is fully reliable for the next race. The simple fact that it still starts, runs and drives does not cut it for them. Ever see a NASCAR driver running the car from his last race on the track with beat up fenders and a duct taped radiator hose? I think not. Just a few words to keep in mind. Whew, I am winded from typing all of this!
