How does dash speaker mount?

[RShaips]

I am going to put a new stereo and speakers in my 67 and I would like to use the original bracket and put a couple of speakers up above the radio under the dash. I have the bracket and I did this before in another truck , but I can't remember how that bracket mounts. Does it mount to the radio or the dash? Last time I took out the original speaker and replaced it with 2 speakers that I mounted in a homemade bracket and attached to the original bracket. I want to do this again. Thanks