Looking at the one you say, appears to me it would fit the contour of the dash correctly.
I went with the Laguna radio from LMC when I did mine a couple years ago. It didn't fit exactly like I had hoped, but I made it work. I think this Classic one you show would fit better. Faceplate looks like it has that contour to match the dash. If I was doing it again, I would go with this Classic one.
Consider this though.....the quality of sound won't be as good as you would hope in one of these old trucks, especially with just the grill speaker. We had a speaker discussion a while back about adding speakers in the cab corners, which is what I did. That helps tremendously for volume and quality. 'jrhackett' did a sound bar horizontally right above the gas tank on his, looked real good.
