[Dior55]

I believe my timing is set to about 36 degrees. I haven't checked it in a year or so, so my mind is fuzzy on this.

Going under 50/50 is not going to harm your engine. Running pure water would, of course, but if you keep it to about 10 - 15% you should have nothing to worry about, and you'll see an incredible improvement in cooling abilities!

Frank the mention of air in the system deserves investigation. I used a remote filler T on my upper hose to make sure I was "burping" the system (In fact, I removed my entire rad cap from the radiator and had the opening welded shut). With the low clearances a BB has inside a Cobra compartment, you have to think about certain things that "mere mortals" never have to concern themselves with!