Scale is determined by the scaling units you're using in Max and by how you import the 3DS file. I forgot exactly what the option is called, by gMax will prompt you for something when you import a 3DS - uncheck it, whatever it is, and the scale will be exactly what it was from the scene in Max. There is no error in the 3DS to gMax import that will cause improper scaling unless you choose to let it do so by checking that particular option... I believe it's called scale units?