Vortec is a total useless piece of junk. Instead of using a fuel rail it sprays fuel into the cylinder with plastic and rubber lines. Heat makes those things brittle until the supply line busts and dumps large amounts of fuel flooding your engine. The next thing you know you are replacing an...
Wow that is amazing an engine with 48 more cubes is stronger. Try that with a 305 to make things closer to equal. You are comparing apples and oranges.