OK!
This is a difficult one. The overall diameter is 140mm. If it were 120mm I'd say you'd be okay. The extra 20mm may or may not be a problem.
I was at a local Fry's Electronics store last night. They have motherboards out on display. Some of the motherboards do have very large chipset and mosfett heatsinks. If Microcenter is like Fry's and has the mobo's out on display, then maybe you can check for fit right at the store without buying first. Just explain to the sales clerk you don't want the hassle of buying the blue orb, taking it home to find out it doesn't fit, and then returning it.