I've done this before and they will turn out great.
Here are some questions to see if it will work.
How many lights do you have?
What wattage are they?
What temp are the lights? (2700k, 6500k, or other)
What is the temp in the grow box when running?
Do you have good ventilation?
Is there any light leaking? (if light gets out it probably gets in too)
Will I have enough room?
These are some starter questions but there's a lot more to it than just these.
Here are some pics of my current box and a grow from a few years back using a different box. The pics are of a single plant that I LST'ed to fit into the box. There were about 18 cola branches on it and it fit inside of 2, 28 gal tubs. The box pictured is 2 of those buckets people get to put beer and soda in at cook outs. My next box is 2, 40 gal tubs with 8 CFL's.
Current box has 4 26w (100w equiv.) 6500K CFL's for vegging. When I flower I'll switch them out for 2700k CFL's. I also have a 90w UFO inside the box but the temps get over 80 so I don't use it. The box from a few years back had 6 CFL's but tended to run hot. Still got excellent results but the buds weren't very dense. Got about 2-2.5 oz. total off of her.
I'd also recommend building a carbon scrubber for the odor because it will get strong. There are at least a dozen different threads on how to build a carbon filter on this forum for $20 or less.
