Joe,
Not looking to be rude or pick a fight, but don't you read this forum regularly? Did you try the search function?
There are 3 guys here that post often that can offer that chuck in 3-jaw or 4-jaw or the entire headstock.
Now, if you are wanting a 1.4" bore chuck to mount to a standard Taig headstock, you're going to be out of luck, as the Taig headstock spindle hole is much smaller.
HTH
Gary
P.S. The spindle hole on the above-mentioned chucks may be 1.3" or 1.35". If you must have 1.4" you'll need to talk to one of the 3 guys mentioned above.