Kerodin

Hi folks, I developed a water leak on the driver side of the engine, somewhere near the head/engine seam. I haven't taken the manifolds off yet to get my eyes on (first time doing it, but it looks straight-forward). The water leak is significant - literally as fast as water goes in, it pours out.

Curiously - every image I can find online of this engine shows a series of 5 freeze plugs down the side of the engine, and "under" the fourth freeze plug (nearer to the back of the engine) there is a threaded plug. But on my engine I can only see 1 freeze plug and the threaded plug is "above" that freeze plug. Any idea why or what I'm looking at? I know it doesn't change the fact that I have to get the manifolds off to find the source of the leak - did Jeep use different engine castings during this time frame or anything?