370z with uprev and exhaust/intake would give it a good go though.
370z - ~340HP and 1,466 kg (from wikipedia and the fact my car dyno'd at 308WHP which add transmission losses of ~30HP)
Z4M - 343HP and 1,495 kg (from some random article on Google)
Would make an interesting race
But then your talking stock vs modded, and if you read my post I was referring to the 350z, not the 370z, as that was what Rabbitstew was talking about also
Im pretty sure though that its hard to get more power out of the s52 as its pretty much perfect already. Its making way over 100bhp per litre too. Where as the 3.7 isnt running as good as it could. I have heard some mild mods and your running 350-360bhp.