Paul,
If "push turns to shove" I would use two straight pieces of tubing and
by-pass the H-tube. Personally I think the H tube is a weak link in the
system and a hindrance to coolant flow.  It is prone to catastrophic failure
with devastating results to your engine. Ask my wife.
Ken Lewis
http://neksiwel.20m.com/
Vanagon mods, tech info and O2 sensor help