What gear is everyone running

Here's my issue, I had a set of 3:91 Richmond gears installed by one of the best rear end Mopar guys in my area. At 50 mph they whine like the Kardashians if they don't get front page coverage on Yahoo. I'm going to have to pull the case to have the back lash checked so I'm thinking of changing gears to something a little more highway friendly but do not want to go back to the 3:23's. I know I'm going to lose a little performance but it is what it is. I'm running a stock block 340 with a production date of 6-22-67, ported heads with a ported Eddy performer rpm intake, a 750 edelbrock and stock exhaust manifolds. 727 automatic with a shift kit.