Okay, I have an update that is important for ATCS 840 owners. The case comes with two 230mm top exhaust fans. I unplugged the one closer to the drive bay cage since it seemed to draw air out prematurely. Now that it is disabled, CPU temps are about 5 degrees cooler idle!
Another thing I did was add an APEVIA blue LED 80mm fan to the MOBO tray which is blowing air right onto the GTX 260. Idle temps are 6-7 degrees cooler! I ran out of 80mm fans, I'm going to get another one to go right below it which will cool my 9600GT. I just used some double sided tape and zip ties 😀