Thanks for sharing you experience with high milage Astro vans. I will keep my eyes and ears alert for early signs of failure. Since my Astro van is not driven much, it might be a awhile before I hit the 200,000 mark.
I did experience the bent rod (it didn't go through the cast iron block) and blowby with my 79 Toronado (350 Olds engine) at about 150,000. Since I was not the original owner of the Toronado there was a good amount of sludge build up under the valve covers.
I had the valve covers partially of on my Astro about 6 months ago and as with my Honda (owned since new) it was so clean that you could eat off of it.
Both my Astro and Honda has had 2,000 mi oil changes for the first 100,000 mi, then I extended the oil changes to 3,000 mi. Since my Astro has not been driven much lately I switched to Mobil 1 oil.
I am not implying that my Astro will be trouble free forever, but I am attempting to give it a healthy start.
1998 Mercedes E320, 200K Miles
2001 Acura 3.2TL, 178K Miles
1992 Chevy Astro, 205K Miles