He is right Man, you don't need to do this swap, i have 1JZ on my 240, 450hp, 400tq., it's really good set up, i got power fc and 2j cams and injectors. just put some head gasket, 550cc, safc will be fine for 400hp, new seals, new timing belt, arp bolts on head, a single turbo(master power turbo recomedend), intercooler and you are ready to go, i've seem 2jz ge running 740hp @ stock internals with no problem, just check out @ clubna-t.com, you will see, if you need the valve seals, i got brand new ones from toyotas. http://www.youtube.com/watch?v=DxUw4zze3RY
This video was with 350hp 10psi, now it's a lot stronger