I am wondering what others are gettin for temps on there boats, I have replaced and flushed everthing including raw pump&housing, t stat 160 ? Cruising 175-178is and on throttle 180-181?? Is this good?? or is it to hot any ideas would help thanks .

That is a normal a 160 degree thermastat will run 20 over. 180 is normal for 454/496/502 any temp over 200 is bad.

Thanks should I go with a 140?? what do you recommend

Thanks again
Matt

If you go to low on temp is not the best for an engine Mercury engines have an over heat alarm so if the engine goes above 210 the alarm will go off. Make sure you have plenty of water flow through the exhaust