Radio cutout size help needed

[BrianG]

I went to put my new radio in this weekend and soon became really upset. The truck is all painted, most of the wiring is done, etc. It is in the finishing up stages. I did not notice until I went to put the new slidebar radio in that the previous owner had made the square cutout slightly bigger. It was done so well, that I never even noticed and never thought to measure it. The cutout was made 1/4 inch bigger up and down and that is it. So, the new radio didn't really look to hot with an 1/8" gap at the top and bottom. I measured the old stock radio that came with the truck when I bought it (not installed at the time) and it measures the same as the new slidebar radio. 2 1/4 inches if I remember correctly. The cutout was modifed to 2 1/2 inches. So, does anyone know if GM ever made a radio that had the same width face but was a quarter inch taller, and the shafts were the same width apart? I see that the 68-76 corvette radio looks to be taller. I'm not sure about the width and distance between shafts though. I have not been able to find anything helpful so far be searching the internet. Any help would be greatly appreciated.