Will a 66 toploader work in a 67

Affirmative on the toploader switch. I am in the middle of a '67 to '66 toploader switch (just different clutch pedals, z-bar, etc).

As for the wide vs close ratio - you can use either. Close ratio give you a first gear that is closer (ratio) to the second gear (the actually size has been posted on this forum somewhere).

Make sure you get a toploader for a small block vs big block, if its going in a 289.