winterizing advice please

[yachtsmanbill]

And now the big Kahoona... Last week, the day before haul out, I checked the anti freeze and it was good to about +7F. Being that it was low, I added 3 gallons straight on each and went for a 45 minute ride before the lift to mix it up. I checked it today and its good for -7F.
Since I am going to move and remove the strainers, and all the accesory end stuff to pull the port gear, I am going to dump the whole system and do a flush in the spring. I drained the WHOLE 20kw Westerbeke and was reading the old DD bible about draining the system. Are there any tricks or spots I need to pay attention to in doing this? I found the hidden petcocks on the oil and gear coolers. Do I need to pull the T stats out? The heat exchanger looks real good through the cap hole; should I leave well enough alone? Both mains ran at 180F pretty consistantly. I'll probably break all the hose connections on the raw water side. Comments? Questions? Advice ! ws