Like custom said if well maintained.. that is the key factor. You can have engines that weren't taken care of, die at 50,000 miles, but you can have engines that are taken very good care of, see [like 1993SLE mentioned] see almost 400,000 miles. Oh yeah, and custom, not all '92s are EGR-less. Some are, some aren't. I believe the majority aren't, but don't quote me on that.
The largest limiting factor on our cars, is the transmission. It is the weak point on our cars.. and quite frankly, a large one at that. So take good care of that tranny too! If you already are seeing 150,000+ miles from your car, and nothing major has gone wrong. Don't be suprised if that enigne makes it to 250,000-300,000. Like I said, good care, loving, and maintenance are key