IDK if you can put in a 4.5 crankshaft......but you can bore and sleeve the cylinders out to make your block a 4.5L block
I wouldnt hold my breath on VVEL tuning. GTM posted a video saying they accomplished approximately 800WHP. I personally think that a 400bhp N/A 370z is very achievable
P.S. I know what he means just the way he asked was funny to me