althought the s1800 was discontinued in 1989 i think although a weaker diesel , it was a much more reliable and longlasting emgine, we still have 1988's running while 1996's are on the road to retirement. which engine is better overall.
I bet that S1800 didn't have a 6.9L in it or you would have said the S1800 engines were crap. My guess is it had a 9L if it ran so well. They were a great big beauty.