As already mentioned, diet is key. If you aren't gaining any fat increase calories until you start to then back off a hair. You want to be right on the edge of adding fat. In fact don't worry if you add a few pounds of it. It's alot easier to lose fat then to gain muscle. Just wait a while after PCT before trying to lose any fat or else you will lose muscle as well.
That being said, I would up the dose to 750 as well. The sides shouldn't be any different and the gains will be better if the food is there.
Other than that don't overtrain. If you aren't getting stronger each week then you probably aren't eating enough. If you are eating enough, but are still stuck then you are probably overtraining. It is harder to do on gear, but not impossible.