im also talking 600 at the wheels...my old engine made a best of 467 all wheel kilowatts running low 10's and revving to 9500rpm...its over 600hp at all four. Long engine was all Nissan except pistons, camshafts and rod bolts.This guys talking 600 at the wheels matey ....
My engine makes 670 at the crank , which is about 560 at the wheels.
Sure I have never had any issues , but given that you can buy some pretty neat aftermarket rods for $1000nz now I would suggest fitting aftermarket ones.
When and if I rebuild mine I will fit new rods, and also raise the rev limit (currently 8400)
Mine are shot peined factory rods with oil mods and arp 300zxtt rodbolts.
It all depends on budget and how much caining its going to get, rods usually let go downshifting also.