A few suggestions/comments:
- Be sure to change up your workout on a regular basis. It's not a bad idea to do quads one workout during your split and hamstrings and calves in another workout for 6 weeks or so.
- Try something like German Volume Training to throw a wrinkle in your training
http://missfitchick.net/GermanVolumeTraining.html
- Try and have whey and complex carbs about an hour before your workout. I also like a cup of coffee about 30 mins before a workout to give me a real boost. No matter what time you workout, be sure to have simple carbs and whey protein after you workout. Since you're working out later in the evening, i'd also add some casein protein that will slowly digest throughout the night to prevent going into a catabolic state
- I'd try to add triceps to your split, which will probably have a bigger impact on your arms than working your biceps - but try to do both.
- Be sure to lift heavy. That said, for legs, I like to bump up my reps to around 12
I hope this helps.