Understandable. I bought an LS3 for my IS, but then decided the car wasn't nice enough to warrant the effort and expense, so I shopped for a nicer one for the swap.not a bad idea but I wanna see what the 2jz can do.
After 6-8 months of shopping, I ended up finding a nice clean already-turboed one for fair money. Needed some work but had good bones... Originally the scheme was to get the 2J/r154 powertrain all squared away and sell as a complete engine/trans/ecu package, but instead decided to keep the 2J and play with it for a while.
Every time I floor it and wait for something to happen, I think about that LS3 still sitting on the floor of my garage.
An LS3 shaves over 200lb off a turbo 2J, and that's up front where it counts most. A stock LS3 is good for ~395whp, but we all know that can be improved to 425 or so with nothing more than a fairly mild cam. So the peak power of the LS and 2J would be about the same but the LS3 would obviously have a shit load more bottom end torque and response.