I am not sure what you mean by "What pin".... Unless you mean 6 pin or 12 pin.
We installed a VMSPC in our 1996 Sahara. You run the software on a computer and ours used an interface thru a USB connector. We originally purchased a 6 pin connector but it would not work. So, we switched to a 12 pin (I think) to attach to the transmission port below the steering wheel.
Happy, yes. The computer sat on the "hump" of the insturment cluster and displayed all the information I need. Speed, Tach, Temps, Turbo, Fuel, etc. It was all there and easily visible at a glance.
We sold the motorhome, but wish I could adapt the system to my car.
Al Wilson
Former 1996 Sahara 3550
Cat 3126 250HP