Well it is well known that the fibers more responsible for size are your type II fibers. Type II fibers come in three varieties: a (1-4 reps), b (5-10 reps), and c (11-15 reps) or something very similar to that with those rep ranges. The best plans in my opinion for people looking for pure hypertrophy on lagging muscles is to hit all three of these rep ranges with low volume on lagging muscles. Everyone always wants to hit lagging parts with more volume but it is very counterproductive, hell even I have a problem with it a lot of times.
I am not sure of your measurements or current weight but I would try doing a drop set on your last set of biceps and maybe only do 2-3 sets of actual isolation bicep exercises. Train your biceps on lat day, they will get PLENTY of work on lat day. Heck I know some people who don't train biceps because they were lagging and just the lat work they did made them grow. Drop sets though will allow you to hit each rep range. Put enough weight on there to get 4 reps to positive failure (not negative), then drop weight IMMEDIATELY (helps to have a partner) and do enough for 5 more reps, then drop enough weight to get 5 more to positive failure.
Another problem with lagging body parts is the androgen:cortisol receptor ratio in the area. This explains why some people just have 1 or 2 freakish body parts and a lot of others lag bad, the cortisol receptors are too much for the androgen receptors in some cases. PTOR or protein turnover rate is another big proble m.