hehehe..niiice..that is one ghetto rig

Overheating issues on the 5870? Try putting a fan on top of it. This way it will blow cold air right on the cooling fans.
I put the 5970's spare fan on top of the 5870, temp dropped to 84C almost immediately. Thanks!
I definitely need more fans on top of the 5970 now

Btw, the fourth card is a 5850 xtreme. Does at least as much as one core on the 5970, liking it very much.
using paper/carton-based [surrogate]cases is dangerous, guys.
It's a temp deal, also I'm keeping an eye on it. Should the PSU get hot, I'll put it on the floor (using its fan right now, till I get more fans)
I could also isolate the contact points if it's too much heat.