I think 1000whp on a stock block, what was designed for 1/3rd of this power - in n.a. form - is already outstanding!!
Why 1000whp...because of the following link (from an older topic) where we can see inner details of the s54 :
https://www.bimmerboost.com/showthre...-ENGINES-VIDEO

About the 2JZ, everything looks even bigger and stronger, as explained here :
https://www.youtube.com/watch?v=FHSvVIkxPB4