Need a new training split

Guys for last few months I've been kind of dicking around - medium intensity, too muhc booze, etc etc - but now it's time to get down to business.

Before I always had at least 3 workouts/week which usually looked like this (not necesarrily in order or execution, typically 4 sets of each varying in reps different weeks, also I mixed up exercises but these are the 'cores' i suppose):

WORKOUT 1: BACK/BIS
dumbell row
lat pulldown
setaed row
standing barbell curl
seated preacher curl
alternate dumbell curl

2 CHEST/TRIS:
bench
inlcine/decline bench (depending on week)
hammer press
skull crushers
cable pulldowns
dips/kickbacks

3 LEGS/SHOULDERS
military press
arnold press
bent over lateral raise
squats
machine leg curls & extension
standing calf raise

My goal? Gain as much muscle as I can in next 3-4 months! (w/o too much fat of course).

I'm looking for advice on a new training split for 3-4 workouts/week, and going for about 1-1 1/3 hours per workout.

PS: I'll be posting updated pics of me soon w/stats.