Cleaned my heat exchangers before re-installing during the head gasket change, seems 30% were choked with scale / buildup. she should run at optimum temp now. Worth the effort to rod each passage with the gun cleaning brush. Flushed and blew all tubes with air for full flow. New thermo stats should also regulate temp for optimum fuel milage.
Last 2 winterizations, flushed with radiator cleaner, that seems to be a waste of effort.