I cut right at the edge of the old dash and cut the new dash to fit. So I was able to retain all the clips and defrost ducts of the old dash. There was a about 2 1/2 to 3 inches that had to be taken out of the 55 car dash to make it fit. Also the humps had to be relief cut and bent into shape at the rear. I'm not finish yet I'm gonna add metal in the kick panel area to make flow like the old dash, but thats the easy part.