radiator leak at overflow fitting

[BillyT]

The wife informed me today that the car ( 84 300tdt) was smoking a little when she turned it off today. When she pulled in I popped the hood and turned it off and saw steam coming out the barb connection at the radiator that goes to the overflow. The barb is cracked halfway through. Do I remove the barb and tap in a brass fitting or ???? I'm also super busy tomorrow but can work on it friday. Can she drive the car tomorrow if I make sure the radiator is topped off or am I asking for it? If anyone knows the specific size/type of replacement fitting that would be great.

thanks for the help!