1980 diesel Step Side?

[vvp step side]

Does anyone know what year or model square body 3/4 ton four wheel drive had the factory tac in it?
What option code should I be looking for to find a factory tac?
I would like to put the factory tac in this step side.
I did it in my 76 blazer and it looked and worked well.
Dammed if i can remember the year of the wrecked 3/4 ton Chevy I found.
It had the factory tac in it with the small fuel gauge.
thanks again for the reply's they are very helpful.