[roll_the_dice]

I think it is 16 gauge. That is what I bought to do the same thing. I am repairing my radio cut out and at the same time filling in my ashtray opening to put an A/C vent. I haven't done it yet, but I did cut out the sheet metal for the ashtray cover up. I drilled out the spot welds on the back of the dash panel for the ashtray holder and opened up the opening a little since it was rounded on the inside...below is a picture of what I am doing and what it will look like when I am done. Hope that helps.