Re: Gibson 490R with and alnico 5 mag?
Nope, but it's probably worth a try.
I bought a set of Seths to replace my 490s. I turns out that the Seth bridge sounded weak and thin compared to the 490t bridge, so I kept the 490t. However, the Seth neck was a step in the right direction: not as strong or as muddy as the 490r. Still, it wasn't as big of a step as I had hoped, so I swaped the A2 in the Seth neck for an A5. Much better.
I realized that the Seth neck != 490r, but I bet an A5 could clean up the muddiness of the 490r. My hunch is that you might have to drop the bass string side, as the A5 might make it a little bass heavy.