Hmm maybe, i didn't notice any changes in temps or noise after i did it. But what i had before was the gfx card getting clogged full of dust and none in the rest of the case, i think the air was coming in through there and getting sucked up into my gfx card. Ive just got 2 fans in push pull config, and a tagan psu which has 80mm fans, apparently they only run at 500rpm when idle so that shouldn't make much difference. I think this is what ill do then, mod some sort of dust filter over the rear vent and see if my temps change.
Mark