The good old 383's we had with the "thin" webbing had the tar beat out of them. And werent balanced and blueprinted like todays builds. They did ok if I remember. Now everybody needs a 230 block or their 475 hp build will blow up...FWIW I saw 2 400's for sale with real bad core shift. They arent Unicorns. They are a good building block for a wild bracket engine or torque monster. Most people wont be building 780 hp strokers with them anyway. My 2cents.
