Quote from Brighton:
OK, I think I understand your scenario better, except for one thing - your mention of the need to sell stock to raise cash to buy in the original short calls. Your underlying should have moved up in price and your call position is being marked-to-market, so unless your account is facing a margin call from unrelated activity, I don't see why you need to raise cash to buy in your original short calls - you should have sufficient liquidity to do that now.
If you do sell some of your stock prior to buying in an equivalent number of calls, then yes, you are going to be naked some short calls. Is that playing with fire? No idea, but it's not for the inexperienced and depending on the type of trading privileges you have, it may be disallowed so the order(s) won't go through that results in a naked short call position.
If you're bullish and the stock isn't prone to extreme moves in very short time spans, I'd get your orders and limit prices lined up, buy in the lower strikes, sell higher strikes, and leave the underlying alone. And there's no rule that says you have to sell calls on the whole position; if you're very bullish just do a partial write.