Welcome to the forum!
A couple of key issues here, because I believe the following may be of your interest, and may also be in the interest of other readers on this forum (and regardless of your "technical question" only relating to whether the T5200 will fit in a T60 or not):
1. If you really want a noticably
speed increase, I'd certainly suggest that you get a solid-state drive (SSD) first, e.g. an Intel X25-M, rather than upgrading your CPU. See e.g. the thread SSD Upgrade for T60p How-to? Need suggestions
. If you have the energy and interest to learn more about SSD's in ThinkPad's, I'd suggest that you search
this forum for information about peoples experience with upgrading from a standard mechanical hard disk drive (HDD) to a SSD, compared to the speed increase if upgrading the CPU to a (in your case: Slightly) faster type.
2. Before upgrading your CPU, verify that your motherboard is Rev. 3; use e.g. the free program CPU-Z
. Check the revision number in the "Mainboard" tab in CPU-Z.
3. Be sure to upgrade your BIOS to the latest version supporting Core 2 Duo's before
you swap your old Core Duo to a Core 2 Duo. You will find all T60 downloads at Drivers and software - ThinkPad T60, T60p
4. Consider swapping your fan if upgrading your CPU to a higher TDP model (Thermal Design Power) – about replacing a T60 fan see the thread Fan for T60 2007-CTO
and especially this post
. Get the T60 HMM (”Hardware Maintenance Manuel”) as decribed in that post, and also see the various videos etc.
As to what ”speed increase” you can expect if upgrading a T60 from a Core Duo to a Core 2 Duo CPU, I suggest you read the following threads: T60: Planning on swapping out my T2400 for a T7600...help?
and Upgrade processor to Core 2 Duo
and Thinking about Duo 2 Core upgrade on Z61m?
and T60: Upgrade Core Duo to Core 2 Duo?
and Big difference between Core Duo and Core 2 Duo?
and T60 Core Duo --> Core 2 Duo
and Core 2 Duo Upgrade
and Mobile CPU Wars: Core 2 Duo vs. Core Duo
Again, I hope the above may be of some
use for you, although you didn't ask about all I explained above! Good luck!