Wrong.
Camaro engines do not work better. Here is why.
Shitty factory internals
High compression
Supra engines work better. Here's why:
Great factory internals
Low compression
Anyone who argues otherwise is just blowing smoke.
That said, I've ridden in a twin turbo LS1 (built internals, stock head, mild cam, all other bolt-ons). It was fast as hell, especially on just 4psi of boost. I'd say it was about as fast as the fastest BPU 6 speed I've ridden in.
The main limiting factor in the particular car I rode in was the injectors; the guy (Cannon @ LS1.com) had stock fuel.
Planned upgrades on the TT LS1 were fuel and heads... I can only imagine the kind of power he'd be making after that. He'd probably have to get a new rear end and tires to hold the power.
Once you start building the motor and dumping TONS of money into a car, it doesn't really matter what you started with.
But the fact remains, for forced induction, the 2JZ as it comes from the factory is leaps and bounds ahead of the LS1.