recently switched my 440 over from an electric water pump (w/o a t’stat) to a FlowKooler water pump and 160F t’stat. I noticed about a 20 drop in temperature. It will idle at 185 for over 30 minutes without moving the gauge.

I am running a 26” 3 core as well but I do have dual electric fans. In my opinion, the water pump swap may be the low hanging fruit - cheapest and quickest install vs throwing an electric fan on it. Just my 2 cents.