Looking to buy/build 500-600 fwhp 360

**** ,I regularly take my 340 past 6 grand with a balanced factory forged crank and stock rods.
The source was David Vicherys (sp?) book on building a SBC for 600 hp on nitrous. I should have stated I have no data for the dodge 360. Maybe the crank is bigger for the LA 360 vs SBC 350. I am happy to be wrong, but apparently it is the harmonic vibrations that eventually break a crank. Obviously metallurgy and overall size of the journals make a difference.