Just wondering how imperative having the counterweight is for the earlier manifolds with the heat flap? I just put an NOS manifold on that has the flap inside, and I can get everything for the whole counterweight setup, but I was wondering how important it actually is? Obviously it could get funky in the summer if the flap is only directing the exhaust up to the intake manifold, but Is there a way I could just make sure it's only diverting the exhaust down? So I wouldn't have to worry about the flap sticking open or closed if the bi metallic spring fails?
Thanks.