There is no mention exactly what engine this is besides saying it is a stroked 408ci Chevy V8. It could be a LQ4/LQ9 based engine. Either way the Silverado is running a 83mm turbo at 19 psi good for 1,000-1,100 horsepower. Watch as this truck does multiple passes and presumable (owner says it’s a daily driver) drives it homes afterwards.
Source: LSxTV and High Tech Corvette