Greetings from the UK.
This conversion was carried out recently on an IS200. They fitted the GS430 motor and 6 speed manual Box from the Supra.
Sorry. I don't know who it was but it was shown on TV a few months back. The company that did it are heavily involved in some sort of racing. Not sure if were an Ozzie tuning firm that did it.
Try a search for V8 IS200 and you may get some info.
It wasn't pimp my ride.