I have some gas mileage issues in my '58 1/2 ton with a rebuilt 283 that starts, runs and sounds super but sucks the fuel(I am even driving conservatively). Now that I have a working temp gauge I know it runs at a steady 160 degrees. Doesn't vary even on a hot day. My question is should I put in a 180 degree or higher thermostat? will a hotter engine burn gas more efficiently? I just gased up and will check the mileage at 160 degrees.