It sounds like you have a pretty good drill press. It deserves a good chuck. You now have an 11N Jacobs, which is the best series chuck Jacobs makes. The 11N is the smallest of the series, the 14N is the 1/2" capacity version. The 5/8" capacity 16N only goes down to 1/8", so you would have to change back to your 11N for smaller bits. The Jacobs chucks are now made overseas, and I have seen posts critical of their quality. Would you be satisfied with a good used chuck? If so, many are out there.
Most industrial chucks are built with a female taper in the chuck body. An adapter with a taper that mates with the chuck taper is sold separately. What you need is a chuck and an adapter that has a #2 Morse taper for the spindle end.
The chucks will have a taper number on them. Heavy duty chucks, like the Jacobs or Rohlm ball-bearing chucks, will have numbers like 2 or 3 that indicate the taper. Both the 14N and 16N have #3 Jacobs Taper bodies. You can buy a #3JT to #2MT adapter quite inexpensively from a tool supply company.
You can change the taper adapter if a used chuck has the wrong one installed. Jacobs makes wedges for removing the old adapter, and a well-equipped machine shop should have a set.
