parts source

Make sure the kit you get is for the 66. I see springs in the above photo that are for the '69 up brakes. The shoe return springs may be the same for both types but I don't know for sure. Check that out before if you can.
You are correct. I ordered one and should have it tomorrow. They show no part number for a 66. The return spring looks to be the same and that's all I really need.