Cubic inces convert to liter by dividing by 61. So 5.0 inches is actually 305, they round it to look better. By this formula a 5.3 would be about 327 inches, and so on. however you need to be aware the new Vortec line has nothing in common with the old small block. It is now called the ls line, same as a Corvette Ls1, hope this helps you out