I have a 1985 formula with twin 260/alpha 1s. The starboard motor runs 170 all day long the port motor runs 180 when crusing and if I start driving hard it will creep up to 185-190 never higher. I have good water flow out both pipes. I have replaced the impeller and the impeller housing which had some signs of being run dry. That didn't change anything. Any thoughts on what I should check ?

hi . the risers should be equal temp unless some blockage, your gauges could be off a little. you thermostats could need changing, your power steering coolers could have weeds in them. A laser thermometer can help 'pinpoint' some issue. lots of stuff can cause this.