Why isn't speedo working correctly

[sneakers93]

When I got the car the miles nor the speedo worked. The clutch went out a couple weeks after. I bought a 10 spline clutch but when the shop was trying to install it they told me it was the wrong one because the car has a upgraded tranny with a 26 spline input shaft and its a tr3550 so I got the right clutch over nighted. My dad did something in the wiring to fix the miles so the miles work now. After he did that and got the miles to work the speedo worked but now it only goes to 20 what might be wrong?

 

[01yellercobra]

If the 3550 doesn't have an electronic speedo pick up then that's your problem.

 

[sneakers93]

What all do I need to install it and where could I get it from? Speed cal wouldn't work?

 

[sneakers93]

What all do I need to install it and where can I get one from? A speed call wouldn't solve the problem?