I can tell you first hand since I have built a 450whp and a 850whp 2jz240 that if 600whp with reliability is the goal, the 2jz wins hands down. Without going into a 5 page report on the subject at hand think of it this way. Which would last longer, A fully built 2jz making 1200whp that is acually driven or a stock bottom 2jz that is making 400whp.

Now do the dame with the with the sr. YOu want a 200whp motor to make 3 times its original safely and more reliable than the 2jz that only wants to double its hp with a block that can triple it without modification OK I am done