[Gav]

I rekon you have it covered Dave!
There is a huge difference in tuning for power versus emissions.
The ability for an engine to pass emmissions comes down to more than the intake, head design is a huge factor and I'd say Mr Damage will have a trick set of CNC'd heads on his, along with some pretty snazzy pistons, rings and cats to help what is a 50year old design comply with modern requirements.
Getting a cammer to pass emissions is a pretty cool result in my book.