I've literally spent most of a entire week playing around with settings and trying to find the sweet spot and I feel like I'm pretty much there. As you can see, I actually underclocked my cards to get these hashrates. Stock clocks are 1100 core/1500 memory. Unfortunately the default voltage is about 1.2 volts on my cards and its locked (@#&($$^(@&$!!), otherwise, I'd be able to save 100-150W easily by undervolting.

I'm seriously thinking about getting rid of these cards and getting 7950s or 7970s that don't have the voltage locked. Having the voltage locked is such a huge drawback, I'm just wasting too much power right now.
Is there a list of which cards are voltage unlocked anywhere? If not, would be a useful list to start, especially for LTC mining.
I know any Gigabyte cards from late 2012 onwards (i.e. any 7970 after rev 1.0) have their voltage locked. It's a hardware lock to, no new bios is going to unlock it as far as I can tell.
Honestly, the easiest way to tell if a card is locked or not is to go on Newegg and find the card you want. Then read through the feedback for that card. There's usually people commenting on how well it overclocks and what they were able to achieve with voltage/core/memory settings. Pay close attention to the date the feedback was posted though, because cards get new revisions and the new rev. might be locked whereas the older rev. wasn't locked.