Anybody used the Dallas Speed Cal for 99+ T45 in a 96-98 GT?

[Speeds8erM-1]

I know the 99-01 T45 is electronic speedo, and my 98 is cable style, and I know you can swap the tailshafts to make a newer one work in a 96-98, but I saw a post saying the Dallas Speed Cal should work, but havent seen anybody that has actually done this, other than with T56 swaps.

Has anybody actually done this? Did it work decent? I have access to a cheap 99 T45, and possibly a Dallas Speed Cal as well.

 

[TheSalad]

Yeah, this is what I have. There are two SpeedCals, one is normal, and the other is an "Extended Range" one. You will need the extended range one.

The extended range one amplifies the signal or something like that because the regular speedcal won't be able to correct with the new transmission.

Let me know if you have any questions.

 

[Speeds8erM-1]

How accurate is your speedo with it? All you did with the newer T45 is drop it in, and plug the speedo into the speed cal and it's good to go?

 

[TheSalad]

My speedo is currently having issues, but I believe they are not related to the speed cal. When the speedo does work, it is within 2-3 MPH. There used to be someone who could fine tune it, but I am guessing only the people at Dallas Mustang can help us now.

I did the install of a normal speedcal first when I put 4.10s in. Then later I replaced the transmission. When I replaced the transmission I realized that something was wrong when I was going 150MPH on the freeway when I was going less than 60MPH. When I got the ER (Extended Range) speedcal, I think I just chopped the wires off the old box and put the new box in there. Worked fine from then on.