Yeah, Brett is very particular about that. The 1J uses the IS300 engine mounts, but sits lower than the 2J in the IS300. Both of course make the car a little heavier in the front end than the BEAMS motor, but the trade off it lots of power and LOTS of torque.
Myself and one of the other guys in our club had a brief ride in IS1000 around the block. It didn't straighten up/hook up until 3rd gear. I just couldn't stop laughing, and no, the NOS wasn't engaged
In fact, it was only running about 8psi. Astonishing stuff. You look at that big turbo and you think, lag, than massive power, but it's nothing like that, just instant revs, instant power.