Dude, that is some old stuff. I don't even remember the socket/slot for those.
you're main problem will be one of two things... different sockets, and motherboard compatibility. If the two CPU's are the same socket or not should be pretty obvious. As for the motherboard, you will have to do some research.
Find the make and model (manufacturer and model number). If you currently have the lesser one running, download Everest and run it to get the info. |MG| EVEREST Free Edition 2.20
Once you have that, Google for it, adding the word "specifications" with the manufacturer and model. What you are looking for is the highest compatible CPU for the motherboard.