350RWKW is not very hard, nor is it that expensive.
One of my customers is running a ECOTEC with a turbo and it is making 465RWHP.
The best he has been able to run so far is a 11.01 @126MPH.
The only modifications to the engine is a set of heavier valve springs.
The turbo kit is from Exile Motorsport and it is running E85 and 21PSI of boost.
I am not sure what the turbo setup cost, but that was the most expensive part of the project.
The other costs were tune, injectors, surge tank, some wiring, a couple sets of drive shafts and a clutch.
The car is a VY, full street weight, street shocks and springs, with a GETRAG 5 speed.
Once he can afford some decent drive shfts he is going to be coming back for a more aggressive tune to see if we can get close to the 500+ RWHP mark on a poor old stocker.