Looking to buy/build 500-600 fwhp 360

my 340 had a stock bottom end bsalanced never had a problem except for noisey lifters if i revved over 7500 rpm
What's the purpose of spinning it so tight? Unless you have a carb,intake manifold, cam to support those rpm's,it's pretty much useless as most cams power band starts to drop off around 6,500 rpm's.