Welcome to the Team Joel!
I think the nicest part of the car is the paint, totally assume flame job! I would never have thought to use green and yellow or white paint to make those realist looking green flames.
I have no idea what Chris built for him (Chris Straub is a professional engine builder out of Bristol TN), but knowing that you don't run more than half of your normally aspirated horsepower as nitrous I'm guessing a 500 or so horse 383.
I had a 582 BBC in my '85 Impala. But the mid eighties series on B-body cars are considerably smaller (about the size and weight of a 1970 Chevelle) than the seventies Impala he is running in sunny Sweden (pulling a wheelie on a cold track is impressive).