Phono preamp gain computer at kabusa.com (click on phono preamps and scroll to the bottom of the page) shows you need 63 db of gain. I'm with Kal above; unless you are running a system with very low overall gain in your actual preamp further up the line (say a passive) or extremely low efficiency speakers you need less gain not more or, a lower output cartridge. Sounds like the integrated you are running has a bit more gain than the component(s) you replaced.
Once you hit into low output MC's, getting the gain right is very critical. My guess is that the "higher noise floor" you are hearing is a result of too much gain and the noise and hiss being amplified as a result of that. You might also have a very slight hardening of the sound as a result of too much gain. Go higher gain and your problems will become even worse and your sound quality will deteriorate even more.
Once you hit into low output MC's, getting the gain right is very critical. My guess is that the "higher noise floor" you are hearing is a result of too much gain and the noise and hiss being amplified as a result of that. You might also have a very slight hardening of the sound as a result of too much gain. Go higher gain and your problems will become even worse and your sound quality will deteriorate even more.