MSI Gaming 9 AC - PCI Express Slots Position

Question

Hey guys,
Just recently I finished setting up my new machine (even got a problem while updating the BIOS on the mobo, which has been solved with the support from folks of this forum =D) and then after I while using it, I realize that the space between the first and second PCI express slot is just so small, it's my first time running a SLI machine, got two GTX 970 G1 Gaming from Gigabyte and they are so close to each other that after installing some monitoring programs, I can check that the temperature on the first card (the one with no room to breath) goes almost instantaneously to 79ºC~80ºC when playing a high demanding game while the second stays around 64ºC~65ºC, with both cards running at 100% fan speed.
And since the standard thermal limit of the GTX 970 is 79ºC, the gpu clock goes way down from almost 1400 mhz to 1100 mhz to cool it for a while and then boost it again, turn it down to cool it again (and again, again again), there is a noticeable difference of fps while this is happening so I don't know if that is something that is suppose to happen on SLI system or if the cards are really too close to each other, I have check some other motherboards and even the Gaming 7 AC has those two first slots with more space between then.
Is not possible at all to use the third slot to SLI on this mobo to make it work on 8x? There is a solution or some sort of modification to address this? I attached a pics to illustrate it better too.
Thanks!

Answer 1

Thanks for answering guys, my case is a Corsair Obsidian 750D, so there's plenty of space and also two front in-take fans and one exhausting on the back (I also have a Corsair H100i cooler for the CPU and when gaming, set the fans to maximum speed), in some cases I see almost 20ºC of difference between both cards, yesterday I set the temperature limit a little bit above the standard 79ºC to 82º and while the main card was running on constant 82ºC, the second was somewhere between 62 to 64 degrees, I'm kinda worried about this temps and how it could affect the cards, if they are heating way beyond they should and it if could impact the durability of the physical components, cause a sudden malfunction or literally fry something. Am I worrying too much about it?
It's a shame that it seems to be really difficult to find a XPower AC Z97 board here in Brazil, MSI could have also leave a little bit more of space like the Gaming 7 has, there's a technical reason on why they leave the PCI slots closer to each other on the 9 comparing it to 7?