Might as well give it a try, if you can lay your hands on some cheaper fans, you might want to experiment a bit.
I'd say there's no point cutting the "frame" in a part of the fan sits next the the length of a fin... you might be able to almost completely remove the other 2 sides, though. One side has no support going into the center, I'd say you should be able to cut it (just leave the corners, for rigidity/stability).
I also still think you're talking about a pretty high speed fan necessary to push that much air in there. (Possibly electric blender or drill noise level)
The concept may not seem much like [url=http://forums.xbox-scene.com/index.php?showtopic=613191&st=105#entry4094035&highlight=copper+heat+sink]DuBob's
(DuBob's) copper heatsink, but in some ways it is. You're trying to get better cooling through the fins' surface area. You need much faster air movement and higher pressure. His sink originally had more surface area, but he couldn't get the airflow without higher air pressures ----or more space b/w fins, which would throw his whole idea out the window.
If you know anybody whose really into computer hardware, they can probably get you some problematic fans, that will work well enough for you to try some things.
I don't mean to piss all over your idea or your creativity. If you really search through the GPU heat sink replacement threads, there is not a lot of thrilling success there. Maybe you will have the end-all and be-all replacement, sort of like the x-clamp replacement.
My 360 has 6 months left in warranty, then I go external DVD drive with a massive PC processor heatsink stuck on the GPU [+ higher cfm fans]... it's likely to look dumb (I'm a duct-tape fan), but I'll be going for cool.
I may even look for a way to strap the current GPU heatsink to the underside of the mobo. (If committed to ugly, why avoid Fugly
?) I just don't get the guys who prefer to shell out $300 for a new console every 15-30, rather than have their console not look stock. ----Sometimes I swear 95% of people here seem to think if a mod doesn't improve
the outside appearance, it has to look
They can all chime in here now, if they like.