I have 1996 F250 without tack instrument cluster, if i swap in a instrument cluster with tack do i have to add a tack wire or is it already there?
Thanks for any insight on this.

 

It's already there. I did the switch as well in my 96 F150. I can't remember which years are compatible, so just to make it easy, get a 96 cluster with tach and it will fit right in.

 

thanks that's the answer I wanted?

 

It's plug and play, just get a cluster from the correct body style (OBS for OBS, brick for brick) and from a truck with the correct number of cylinders and you're good to go. Just did this myself actually. I do believe in the later trucks like you have you can swap the odometer portion (PSOM) and keep your mileage correct as well.

 

Try to stick with the correct year as yours. If you swap from '93 to '96 you'll be repinning the harness.

 

Getting a cluster "from the correct body style" is not correct. A 92 cluster will not work with a 96, for instance. Again, I can't remember which years can be swapped for which years, that's why it's just easier to swap one out of the same year. Also, the donor truck does not have to have the same amount of cylinders. You are correct about swapping the original PSOM though.
I did my cluster swap with a donor '96 F150 with a 5.8, I believe. I installed the speedo/odometer from my 96 F150 straight 6 into the donor cluster, and it was plug-and-play. I now have my original speedo/odometer with the tach and other guages from the donor.