Everyone is wrong.....THe 1jz motor revs faster than the 2j because of the head design.
THe cubic inches stays the same. In Japan all the "big dawgs" are running this 1.5jz setup so they can have the torque of the 2j but the faster revving of the 1j, THe compression again stays the same. You gotta remember in Japan they have a horsepower regulation...that is why the skyline, and the 1j & 2j (mk3 &mk4) all have the same factory horsepower ratings of 280ps. THat is why Toyota did not put the 1jz head on the 2j. Also They did this in order to make more torque down low.