Welcome to the forum!
What's the 7-character model number of that T43 that you're looking to upgrade?
If it's an ATi-based unit (model number beginning in 26xx) the upgrade is plug and play presuming you swap the entire lid.
If it has Intel graphics (model number starting in 187x) the upgrade is not possible.
Excellent! Thank you for the warm welcome as well! Yes it is a ATI based unit. Has the ATI mobility x300. Not sure how much ram that one is.
Only thing is with the T43 is that it has blu tooth. So I am assuming if I have to swap the complete lid I need a T43 screen and swapping the T41 lid will not work because it does not have the blu tooth antenna built in.