Hi and welcome to the board!
You won't be able to get the dash out because it is spot welded a whole bunch of times underneath the windshield to the fire wall. Only way to drill out spot welds is to take the windshield out.
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1962 fleetside: bodydropped,shaved,bagged,custom 64 suspension,clear taillights,custom aluminum parts,rollin on 100 spoke player wire wheels.
http://www.finelinedesignz.ca