I run the Delo 400 30 wt.  It usually doesn't get that hot here on the Oregon Coast for me to run anything else.  And I feel that oil for diesels (20W-50) is too thick and has all the wrong properties for a gas motor. I stick with 30wt, since I change my oil every 2500 miles, and then reuse the old oil for my my chainsaw for bar oil.  And I run Carquest filters.  They got the anti-siphon valve.  And get the large filter, which for some reason is listed as a 85 4runner.  For some reason that is the only year that they list a larger filter for any 22r/re.  All others listed for a smaller one.

But a search here found these postings:
http://board.marlincrawler.com/index.php?topic=50809.0;highlight=oil+filter
http://board.marlincrawler.com/index.php?topic=46220.0;highlight=oil+filter
http://board.marlincrawler.com/index.php?topic=32698.0;highlight=oil+filter

Castrol 20/50 is NOT a diesel oil its designed for high mileage small engines such as the 22R, Chevy 2.5L  etc

Actually  if I'm not mistaken isnt all Delo 400 diesel oil   I know Delo 15/40 is what my boss always ran in a couple of my big rigs i drove.  the only other oil was Rotella 15/40

the 15/40 is almost ALWAYS a diesel oil and has additives to clean the soot out of diesels