what speedo cable do i need?

I'm tired of my broken speedo cable, so I'm trying to buy a new one. Problem is I dont know what cable to get. The service manual says the tire size and rear gear sizes determines the pinion gear size of the cable. the size of my tires are 225/70/14. I dont know the gear size in my 7 1/4" rear.

what cable do I need?

If I change my rear to a 8 1/4 or 8 3/4 I will need a new cable?