Ok, What I am doing right now does seem to be working. Long post so sorry

I had a few questions about my diet and exercise plan.
First of all, I am 5'11 technically, but i'm pretty much 6'0. I weigh 165-167lbs currently, and I have a big frame. Oh, male too.

Heres my workouts- I do 30 mins of cardio a M-F and sometimes Sunday. The cardio is light-moderate, I keep my heart rate at 130.

On Monday, Wednesday, Friday, after my cardio I go and lift weights, typically concentrating on upperbody, like my chest, back, abs mainly, then arm curls if I am still feeling good.

My diet is this basically...
MWF I eat a Atkins breakfast bar on my way to school with my coffee, and I don't have a chance to eat again until 12:30, when I get out, but I go straight to the gym. By this time i've already consumed atleast 30 onces of water, so i'm comfortable working out. On these days i'll get home from the gym and typically have a snack, such as a shake and a advantage bar to get protein in my system. Later on I will always have a full meal, be it vegetables and a meat, or a sandwich (big one) on LC bread.

On T/TH, my diet is basically the same, except I have time to eat in the morning. I eat the same thing, but sometimes i will mix in some LC milk and LC cereal. I also have time to eat again before I get to the gym, which is not until after 4 when class gets out on T/TH. I typically will snack on something LC or make a sandwich on LC bread. End the day with a real meal.

I stay low-carb, under 30g M-F, but I typically do no go LC on the weekends, and if I do, its not 30g, more around 50g. I did this past weekend. But my typical weekend, I will consume 100-130 a day. I do not gain weight doing this, never have, and I jump right back into it on Monday, and continue to lose.

My goal right now is gaining LEAN mass, as I have very little fat left to lose, and losing it by just dropping the weight does not seem healthy to me (I do not feel I should weigh 165, because of my size I should be about 185). I still have some fat around my waist I would like to lose.

Do you have any suggestions for changing my diet, my exercise plan, et cetera, in order to gain more lean mass without dropping below 165? I know some SMALL friends of mine that weight 165...I tell them I weigh 165 and they freak.