While I agree, this may not be enough cooling for major OC'ing, I think it's worth a shot. I am cooling 3 GTX 285s on a triple (so, one 285 per 120 rad/fan), and 1 i7 920 on another triple. I've got headroom on the temp side with my triple on the 920 (generally run at 3.6GHz), so I think a 240 will do a decent job. Yes ... I'm using Thermochills, but only running fans about 800 RPM.

Also, the data that compares the performance of the Swiftech's and the other rads shows they do quite well. It never hurts to have more radiator, but given the lower cost and easier placement/fit of the Swiftechs, I'd give it a go and see if it meets your expectations.