hi guys, looking for some help with an issue i have. i have a 1979 350 chevy engine in my '31 model A coupe and the temp gauge goes to around 205-210 degress and then drops like a rock to 185 which is the thermostat that is in it. i have flushed it and changed the thermostat twice and it still does this. once the gauge drops to 185 you can drive all day and it does'nt go up. once the engine cools it does all over again. the only thing i have not done is change out the temperature sending unit. i have VDO gauges in the car. any help would be greatly appreciated, sic.