So, I just got 2 780 Ti Classifieds this week that I've been playing with today, and I'm left with a few questions, and some concerns.

First, I've been messing with OC Scanner (Normal BIOS, factory settings). The temps jumped right up past 80*C, so I took control of the fans and have them running at 100%. What bothers me here is that the temps are holding at about 82~83*C. There is space between the two cards, and I've got a side case fan (a Gelid Wing 1500) blowing directly on them as well. Seems like a high temp considering I've read these should be running in the 70s. Idle temps are about 29*C

My second question is about overclocking with PrecisionX, but seeing these temps makes me not even want to think about it. I did try some minor overclocking, but I get a lot crashing with minor changes. Usually an error mentioning OpenGL. In the few overclocks I've had that didn't crash, the FPS in OC Scanner was lower than the factory settings, generally about 50% less. 

I think I had more to ask, but can't think of anything else at the moment.

how do you have the cards put into the rig?  in an ATX mobo, you should have 2 slots' worth of space between the cards, otherwise they will simply cook each other.

Zapix
Yeah, I don't have anything in that space between them, and wouldn't even consider adding a 3rd card for that very reason. Thinking about adding a fan on the bottom of the case to take air out from the bottom card, but I don't think that'll do very much. Long term, I know I'd be better off getting a pair of hydro copper waterblocks (or EK since the EVGA branded ones are impossible to find) into my loop. That much is pretty evident. I didn't have heat issues like this with my GTX 460s, and I OCed them on stock air pretty nicely, but they were also external exhaust.

Put some space between your Classifieds; you're cooking them.   The top card needs some space.... BADLY.  Those fans you see, they're not intake fans, they're exhaust fans, so the exhaust heat concentrates and starts to cook the GPUs.

As long as you stay in the low 80s, you're fine

Yeah, I read the classifieds can take higher temps over on overclock.net, but true or not, doesn't mean I want to take any risks. I'll eventually add them to the water loop as I want to overclock them down the line (otherwise I would have just gotten the SC editions).
On the flip side, it's not like I'm doing anything where both GPUs are going to be under full load. 1080p/60 display. The secondary is just there to ensure that I don't see the fps drop below 60. 

Any ideas on the OpenGL time out error I was getting when attempting to OC? I read it could be fixed with regedit, but that did nothing for me.
There was also the lower FPS when overclocking that seemed voltage related. The closer the voltage was to being as low as it could go (without crashing), the better the fps. But any higher and the fps would be about 1/2 of the norm. Never saw anything like that with my GTX460 cards.

Yeah, was doing that last night. There was no change between the cover on (and the fan blowing out) and the cover off. Only saw it got up (and rapidly) when the fan was blowing in directly on the card. Tried a fan on the bottom of the case too directly below the secondary card, but it didn't seem to help. Again, I'll probably fit these into my Swiftech loop eventually. Would like the Hydro Copper blocks, but seems they're out of production. Can't think about it now though, spending $$$$$ to get my car fixed up. After that it'll either be suspension tuning or gpu waterblocks! lol