No drain plug in the H3, pull the lower hose.
To me, and I'm sure people will disagree, you prob. just have a Stat. going bad.
Main issue I found, I'm sure people will disagree here too, The water pump spins to slow. I'd like to find a smaller pulley if possible.
I'm running a 2 core Alum Radiator with an Elect. fan and the cooling system acts exactly the same as stock, Just no leaks.
Idling and low RPM driving temp gauge sits a little over half, 2K RPM's or better it sits at 180 all day.
I just don't think they move enough volume.