The cable type is a flex cable that it vinyl wrapped and the ball would be a swivel ball that attaches to the carb. A matching half on the cable attaches it there. Imagine a small ball joint and you'll understand. You can get these at almost any speedshop, JEGS, Summit Racing or Speedway Motors.com. Lokar is the best one IMHO. This is an everyday thing with all of them so they can be of great assistance to you. The crank type I think is what someone is calling the triangle swivel used on 216/235 engines that allowed for a pull action to be changed to a vertical movement and up to the carb. You can see the pictures of mine in the link below but it is a 235, not a 250 and is therefore probably different. At least you'll get the idea I think.
Hope it helps iuntil someone with a 250 comes along.
