I get a trade magazine called "Motor" that is excellent. This morning I read an article on thrust bearing failures that I thought might do some of you some good. It has some excellent discussion of crank thrust bearings, main cap install, and insight into how to do an engine rebuilt right. I get the paper mag but the article is in a PDF here:

http://www.motor.com/article.asp?article_ID=1656

FANTIC - this might vindicate, to a degree, your thinking on 40 weight oils and bearing clearances. I'd be interested to hear your thoughts on this if you get a chance to read the article.