Debian 32-bit or 64-bit

[Jos Collin <joscollin@gmail.com>]

Hello,

I have been using Debian in my Lenovo Thinkpad T61 from 2007 onwards. I 
have the latest upgrade Stretch/sid on it.

This laptop has Intel(R) Core(TM)2 Duo CPU T7700 @ 2.40 GHz and was 
having 2GB RAM. But this week I have upgraded the RAM to 4GB and 
replaced the HDD with a new Intel SSD 120GB. So which version 32-bit or 
64-bit do you suggest to install in this system ?

Thanks,
Jos Collin