[blykins]

Easiest way to tell if it's a S/O is to look at the front of the engine. If you're facing it, look to the right of the timing cover. If there's a pipe plug there, then it's a S/O.

Also, it will have pipe plugs on the "humps" on the side of the block.

But the plug in the front is the easiest way....and you don't have to crawl underneath a car to check it.