Short or long water pump?

[clemsonteg]

I did some searching trying to determine the difference between the two. I saw the measurements, but I'm not near the truck at te moment and I'm trying to order an AC kit. I am pretty sure that it is a short pump. I have a picture of the pump on my phone and one thing I noticed online is that it appears the pad on top with the plug is different from long to short. Is that a solid determining factor? Here is the picture I am referring to.