yea its probably rated for more, but a lot of times those hp capable numbers are arbitrary. a stock block is good for 600whp for 1 dyno pull. The question is how long. i think the implication here is that this motor can handle 600whp day in, day out, without issues. Building a motor and beefing up the internals is less about how much peak power it can put down and more about how well the block holds up over time to the rigors of actually putting out that power after thousands of miles. the GT28RS are good for 700+whp on the 300zx (VG30DETT) with the right setup, so i'm sure they are good for at least that much, if not more, with the right setup on the VQ37 with a built block.
You should ask sam about getting 1000cc or larger injectors so you can run an e85 tune
BTW, way to go on doing this whole VQ Forced induction thing the right way
