I received this reply from TuuS in another forum. As it seems to be definitive, I thought I'd add it here for anyone who may have the same question. "You can use the discrete heatsink on your integrated motherboard. Actually the best option in my opinion is to go with a T61 heatsink which is designe...

I'm surprised no one has commented yet. From what I know the fan itself between the two heatsinks are identical in size and shape. So the fan on the new heatsink is a direct drop in replacement on your existing heatsink. Thanks very much for confirming this for me, Easy Wind. I was starting to thin...

Greetings, The fan/heatsink combo I bought for my T60 several months ago was apparently the 41W6409 for a T60 with discrete gpu and cpu, but mine is an integrated model which uses the 41W6408 . As I cannot return it, I was thinking of simply replacing the old fan with the one on the new heatsink. Bu...