Manifold Heat Control Valve - stuck close

It just doesnt close completely at idle on the 70s cars. But it is 100% needed for driveablity. I wired it shut to see if it fixed a rough idle issue (it didnt so i undid it)and it sure takes a long time for the stumble to go away from cold manifold even in summer. 100% needed in fall and spring here.

I dont find anything hazardous about holley 1920s. Make sure the gasket is sealing on the bowl and voila. I like cork, i just buy a bunch so i have spares as they are 1 time use i find. 2 years no leaks.

Im sure in 40c heat and it stuck open may be an issue on the highway though, rather have it stick closed if that were the case