They would have to be very careful with classic hits (if similar to Cool 92.5 in Beaumont) as it could easily poach Sunny's market leader position.
Except the demographics where the 104.5 signal is strongest would be all wrong for a Classic Hits format. The east side is heavily Hispanic. West of downtown you have younger hipsters with the rest being longtime residents who have aged out of advertiser-friendly demos.
Sunny doesn't play anything prior to 1980, so there would be very limited playlist overlap.
BTW after a weekend of dead air, the 104.5 signal is now completely off.