Thanks very much, Dan. It looks like 1...you need the template with the center hole locations and 2...you need to have the 3.5 inch metal hole saw to cut the "oval" shape by making two side by side holes. 3...if you don't like what has been done, you'll have some serious work to recover from it. I believe that's why the people who have replied have no cutout up there. Their truck didn't come with a radio, no dealership ever installed one and so there isn't anything for them to see.
Now for another comment: two 3.5 inch circles will at best make a "sort of" oval about 5 inches wide unless those two circles are so close together that they make an oval of 4".
Even then it will not be a true oval as you can see if you make two 3.5" circles with a compass. And cutting this opening isn't a gentle process at all. The template evidently is gone now. I did some searching for it and I found this:
1956 Chevy Truck Speaker Installation Part 1The friend I mentioned replied and said the speaker in their 56 had been put underneath the dash...downward from the radio somehow. My guess is his dad did it not wanting to mess up the cab's interior.
Maybe I'm wrong but I think hiding speakers under the dash might be the best option so I'm just going to offer the radio by itself. Thanks again!
