Well, the car IS defined by the VIN. If the VIN says it's a Trans Am, then it's a Trans Am. This obviously falls into the "heavy modified" class as do most of the Pro Street cars. They're not my cup of tea but they are very fun rides for their intended use. There's a poster on TAC from upstate New York that's probably modified as much as this car, but in different ways. His car is a BEAST and I've been trying for 2 years to get him to bring it to the Nats -- unsuccessfully so far.
At first I was gonna say do whatever, but then again, this is the last 400 equiped Pontiac model, so I really wish he would've done all that to a 1980 or 1981 car. Sure has a lot of time/$$$ invested, I would hope he enjoys all the attention it gets.