LBM will be gained most easily through proper diet in addition to your weight training.
* Diet should include 40-50% protein per day. If you've never tracked this before, you should look at fitday.com, a free program online used for just this. I'm sure you already know that protein is the building block of all muscle in the body (lean body mass) so the more protein "bricks" you take in, the easier it will be to gain the mass.
* If you haven't invested in a good protein whey isolate powder, now is the time. You mentioned NO Explode, so that means you've been around a nutrition store. I find that Red Blast works far better than NO Explode for a few reasons.
1) It contains the creatine needed to help the instant recovery process during lifting sessions; large quantities of it (such as those in Red Blast) will make it easier to lift, giving you a greater chance of pump in the muscles and better lifts means better GAINS in LBM.
2) The Red Blast also contains your NO, but Red Blast is encapsulated so you won't have to worry about mixing any drinks before lifting. You can take it right with a meal about an hour before and will reap the full benefits in your session. Again, better sessions, better lifts, better gains in lean body mass.
Anyway, all that aside -- it is important for you to continue a lifting regimen but if you're after fat loss too (or looking to AVOID fat loss) then
some cardio is necessary. Most of the guys here that do a little cardio here and there do approximately 25 minutes in one session. The other trick to gaining ONLY LBM is Sesapure/Glucorell combo. PWO champions Mike Miller and Kara Bohigian use both and Kara just last week said to me (she and I are friends; I saw her at the Arnold) that it's nearly impossible for her to put on weight when he's taking her Sesapure.
So watch the diet, burn a little fat, increase protein, and invest in good stuff. You'll be on your way in no time.