Cooling problems

I was speaking to a rad guy last week about recoring my rad and my "high" temps (190ish). $600 for recore...lol
Anyway a trick he uses to check for plugged rad is to drain it, then fill the rad up from the BOTTOM. Once its filled, pull "the plug" so to speak.
If it takes longer than 3-5 seconds to drain, its partially plugged.
For each "extra" second it takes to drain accounts for 10% blockage.