ok.the gate valv i used was 1\2. i see the 3\4 valve its recommended.?
The reason I like a 3/4" valve is because I feel it affords a better range of flow.
It's just less temperamental.
The proper way to adjust it is to let the engine idle (has to be in the water) and slowly start to close the valve down, the temperature should start to rise, once it gets near 140°F- 150°F your should be good.
Take it for a spin and you will likely see the temp drop to between 120°F and 140°F.
If it gets way too cold, you will need to reduce your outlet fitting inside diameter slightly.
GT