Should my manifolds be warmer than the risers on my stock merc manifolds? I seem to be running about 150 sometimes going to 160+ after a hard run until it cools. I just changed the thermostat 140 and when I ran the motor I noticed that I could keep my hands on the risers but not the manifolds amd the temps were still the same. My manual shows the water flow to the bottom of the manifold after the thermo opens so I am thinking new manifolds are in order to get the temp down and the hot water out. BTW, I just cleaned and changed riser gaskets this spring and thing didn't look that bad. What is a safe temp? I thinks 160 isn't that bad since cars are running 180+ theros.

I run 160 stats. If you are running stock exhaust or any exhaust that uses the stock water hose configuration than the risers will be colder than the engine because the water going to the risers only went thru the oil cooler and not the engine. The water going to the bottom of the exhaust manifolds went thru the engine.