People have suggested that, but surely the case isnt that bad? There are plenty of fans. To get a case with more space around the GPU's id need a full tower, which would cost a fair bit more than £40.
The GPU's were overclocked at one point prior to this thread, they are now at stock clocks and volts.
Both have nearly new paste, and one even has new fans.
Ive bought a 200MM static pressure optimised fan for the front. Just waiting on that to arrive.
Ive also noticed that there is barely any temp difference if I have the radiator fans running flat out or on a lower speed. Could that be because they are mismatched?
Try underclocking the GPU as well (not sure if it can be done if it's nvidia but AMD GPU's it's easily done in wattman.
As for the temp not changing - do you mean the GPU temp? That just means you're not getting enough cold air in or the fans just have bad pressure and can't push through the rad/out.
You can easily test this - take the side off, see if temp drops, if it does it means the airflow is poor and you're not getting enough air in.
And no, you don't necessarily need full tower, just a better mid tower with no drive bays in front and maybe more space between GPU's and PSU and nothing in the way.
The truth is, getting a whole new set of fans will set you at least £30 even on MM, at that price you might just as well get a new case. I've seen Phanteks P600s on forums (also been one in bgrade for £70 i think) for £60 the other day (which is what I'm using now) and that with 3x140mm intake and 3x140 top +1x140 back will easily dump any heat the case can have, also PSU will be separated from the GPU's.
Some of the fractal designs as well, I've had the define S and that also has nothing in the way of airflow with HDD's and cables managed at the back of case, is wider and also supports 7x 140mm.
Alternatively you could try using PCI-E riser cable and having the 2nd GPU lying further down, that will give the bottom one less air but top one more so at least they should both drop to around 80c'ish rather than 95 and 70.