2JZ rated 320 crank hp. 800/320= <3. Simple math. Built Supras have dyno'd well in excess of 1000 hp on gasoline, others have dyno'd well in excess of 1200 on methanol. No need to make up my mind, it seemed pretty clear to me.
Street Supras have run 9's with single turbos and upgraded fuel. What's your point? Yes, we take candy from NA V-8s on a regular basis.
Anyone expecting to triple stock horsepower on any engine and have the stock pieces hold up is delusional, or has enough money to waste finding out. I am neither, but the 2AZ is already producing over 300 hp on stock internals without catastrophic failures. 320 is twice rated power, Scionspeed already posted a 358 whp dyno on boost with stock internals. I would not expect stock internals to produce 480 hp from the 2AZ without problems just as I wouldn't expect stock internals to produce 960 hp from a 2JZ without problems. It might work, but I wouldn't want to bet the block on it.
I've tuned enough engines to know it is a symphony. I've built enough Toyotas to know they do alot of the hard part for you before you even remove a single bolt to change things. These are NOT Detroit products, they're what Detroit would have done if the really good engineers hadn't gone to other industries.