do you have a spare external you could clone the 640gb?
does u're macbook not work before after you removed the hdd?
i do not think you can simply put the macbook drive into the MBP due to the different drivers etc
what i would do is clone the 640 gb to a spare external drive, formatted the hfs+ into 2 partitions - A for the clone as an emergency back-up and B for time machine
then put the stock hdd back into the mbp 2011 - fire her up and connect the 640gb hdd via an external enclosure/doc/sata-usb adapter
then manually migrate in all u're files you require and back-up to partition B on the external hdd
format the 640gb as GUID 1 partition in hfs+
then bung in u're osx dvd and install snow leopard onto the external and migrate the data from u're external hdd stored in time capsule parition B.
Then swap the hdd around, and hey presto you should have a bootable, fully working syst, with the 640GB hdd
i am sure there are much easier ways, but this way is tried and tested, and i have done several times in the past few months