THERMAC...leave it or remove ? ? ?

[K20JLG]

I have a 84 K20 and I removed the stock manifolds with A.I.R. and installed new Flowtech Headers, but now I dont know what to do with the Thermac ...AKA the flapper and the hole underneathe where the sove pipe went....should I just leave it be or should I block off/ fix it to stay open ? ? Please tell me your thoughts / experience . Thanks

[K20JLG]

and also the vacuum lines to it ? ? ? Please help guys !

[ray_mcavoy]

Hi K20JLG,

It won't hurt anything to leave it as-is. It'll just draw under-hood air (instead of heated stovepipe air) when the flap inside the snorkel moves to the heated air position.

Disconnecting (or completely removing) the vacuum lines should leave the flap in the cold air intake position. Unless something is broken, it only moves to the heated air position when vacuum is applied to the actuator. Vacuum is applied to the actuator when the thermal switch inside the air cleaner housing is below 100 degrees or something similar.

[K20JLG]

Thank you Ray .