W520 cooler for T520 CPU?

[ssd_thinkpad]

I noticed on my T520 i2520 that the cooler has vents only to the left side. The vents to the back side are hidden by plastic. This is like the x220 ULV cooler which only has vents to the left side where the regular x220 cooler has vents to both the left and the back side. That leads me to the conclusion that the W520 cooler has vents also to the back side and is most likely 100% compatible to the T520 cooler. As I run my T520 passive I want to use the W520 cooler to get better results. My old T60 Intel GPU T2400 was cooler than my current T520 cooler as my notebook now regularly reaches 80 Celsius. What do you think?