TH-400 speedo question

[Cme2fly]

Currently, there is a billet plate bolted in place of with the cable should insert. How can I make my existing speedo cable work on my current 400 transmission?

 

[SWOOOSH]

some people block off the spedo with a plate. you will need the gears for in side. i just screwed my stock cable on mine and it works. its not reading rite but works.i never spent the time to figure out what spedo gear to put in to get it to read rite. it just gives me an idea of how fast im going. i think its like 5 mph off.