your point is well taken in terms of initial work to get to 600 hp, obviously starting with 500hp logically is going to be easier than starting with 320.
in terms of reliability, theres no reason a 2jz cant have 600 reliable horsepower, there are 2jz's with alot more than 600hp being used as daily drivers.
at the end of the day for me its just preference. i like the viper's engine and love the vette's motor, but big cubes and natural aspiration dont really do it for me, im just more of a forced induction man and im really not a fan of putting a non toyota engine in a toyota car. to me personally any extra work would be worth it.
in terms of reliability, theres no reason a 2jz cant have 600 reliable horsepower, there are 2jz's with alot more than 600hp being used as daily drivers.
at the end of the day for me its just preference. i like the viper's engine and love the vette's motor, but big cubes and natural aspiration dont really do it for me, im just more of a forced induction man and im really not a fan of putting a non toyota engine in a toyota car. to me personally any extra work would be worth it.