I just went thru this exercise when figuring out what sleeves/tre's to get for a custom steering setup. I ended up looking on Moog's website and sorting by sleeve length, then looking at individual sleeves until I found 11/16-18. Some of the detail pages for sleeves on Moog's site don't have the thread listed, but if I looked up the same part number on the O'Reilly website it actually listed the thread size and length etc every single time.
If you're comfortable with 0.25" less thread engagement per end, then I found this one during my research (4.75" overall length)..
http://www.moog-suspension-parts.com/moog-es2004s
http://www.oreillyauto.com/site/c/de...2904&ppt=C0203