The engine runs on LPG and has a 11.3:1cr. High engine temps achieve no benefit here and only cost power due to less (hotter) mixture entering the engine. I agree the engine could be a bit warmer but don't like the engine getting too hot, get lazy and even start pinging.
I also always try to keep the intake manifold as cold as possible, but with the smallblock design with coolant running right through the intake, that's not always possible.
I'm running with a 160F thermostat, but the engine hardly gets to that temp, only occassionaly during heavy traffic where slow driving.