A 160 or 180 degree thermostat is too cold for today's gasoline. 200 degree operating temp is not I repeat is not hot!! Below 190 degrees operating temp fuel collects inside the intake manifold and burns off as you go down the road in the cruise mode, eventually making the car lean...This is not seat of the pants science but results from analyzing the information from a wide band LM1 air-fuel meter on more than several cars. Low operating temps contaminate the oil quicker as well...As always the disclaimer: it's your car so do what you want and ignore good information.

As to the OP's problem, it's more than likely the
hardware from our good friends at the 440 source where money rules first and quality products for the customer second. Flow schmow, explain how a restriction in a place where that factory has none is not a problem. The restricted passage is not correct so stop trying to sell us idiots on it. Those of you who will accept mediocrity where excellence is required the offshore product will work "good enough"...