I have an old 2310 furnace -downflow and wish to move it to my basement and convert it to flow UP. Is this possible?

The plate on the heater should tell you if it can be installed up, down or horizontal. It is not that easy since fan has to be reversed, AC coil relocated and probably burners too. Craigslist has heaters for sale and updraft is most common. In fact, some HVAC installers will give older ones away to get rid of them.

It's certainly possible to move and modify the old furnace but at what costs? A few estimates of the costs of this project may lead you to consider an upgrade of the system you want in the basement.

(Or did ma0641 already say that?)