heres a couple examples:
something like this:
which is 5/16" on the threaded end and 3/8" OR -8 AN on the barb end
heres another example:
again-- 5/16" and 3/8 hose barb ...
--OR--
an adapter that has 5/16" male flare threads, and 3/8" PIPE thread female fittings, then I could use the above pictured adapter. (2 peices for each hose connection, you see?)
sigh. my brain hurts
mike