1/2” should be fine, that’s about the minimum you’d want but it’ll work. Might want to make sure your engine and transmission mounts are in good shape as you won’t want a lot of movement there.
Yeah, I said right up front it was for aerodynamic reasons, check my post - “air flow and drag”.
My point is that it’s stupid to tune your street car based on what a race car does. Pro-stockers try to run 100-120* at the start of a run. NASCAR runs 300*. Both are detrimental for the life of the engine and highly specialized to that type of racing and class rules. 180*-200* is perfectly acceptable for a street car, even 210* wouldn’t bother me a bit as long as it could maintain it. 160* is basically the minimum operating temp to prevent valve train wear and quite frankly isn’t realistic for a real street car in real world situations.