It is a 195 thermostat and it does reach 195, it just seems like it takes too long to get up to temperature. I just replaced the 180 degree thermostat to see what would happen and there was no change. I had to convert to an electric choke because there is no provision for a divorced choke without the exhaust crossover on the manifold. I am not satisfied with the electric choke and would prefer a divorced choke, but I don't think that is going to happen. I knew this was going to be a problem with the Vortec heads, but they torque they make is well worth it. It runs a 15.3 in the quarter at over 90mph with the new heads which isn't bad considering I'm only using 2 of my 3 gears and it's in a 4200 lb truck.