I am wondering if anyone knows where I could get a hotter than stock thermostat for a 351m/400. Perhaps a 205° -210° range would be good. I have a 195° stat in there now and the motor will run about 185° on a cold day (I have a HUGE radiator, btw). I'd like it to run around 200° or so for better heat without blocking the rad. Any ideas?

 

Don't know of any thermostats over 195 for a gas engine. Understand you don't want to block the radiator but it might be a simpler solution. Most folks want to try and keep the coolant temperature lower in a gas engine but I understand your situation. I had a similar problem in an E-250 460 with a four tube radiator with a 185 degree thermostat, but instead of changing the thermo since I wanted the cooler coolant temps in the summer I just fashioned a partial block in front of the radiator. I was able to get a piece of 1/4" plywood that covered just enough radiator to do the job that I then removed in the spring. Might have to experiment for the right size but it will work fine.
John