Exhaust manifold question. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**TBONE1964** · 10-29-2015, 03:17 AM

To be more specific it is for an "air" system which is short for air injection re circulation. It uses a belt driven pump on the front of the engine and plumbs piping into the exhaust manifolds. This forces fresh air into the exhaust to help reduce emissions.

It was more common on early vehicles (late 60's, early 70's) with California emissions. As time passed, most of these equipped vehicles had these systems removed and scrapped because of pump lock up.

If you buy some aftermarket rams horn exhaust manifolds, they will be made to except the "air" tubes and come with plugs if the system is not being used.

Hope this helps answer your question.
Tom

10-29-2015, 03:17 AM	#8
TBONE1964 Cluster King Join Date: Nov 2012 Location: Junction City, OR Posts: 5,263	Re: Exhaust manifold question. To be more specific it is for an "air" system which is short for air injection re circulation. It uses a belt driven pump on the front of the engine and plumbs piping into the exhaust manifolds. This forces fresh air into the exhaust to help reduce emissions. It was more common on early vehicles (late 60's, early 70's) with California emissions. As time passed, most of these equipped vehicles had these systems removed and scrapped because of pump lock up. If you buy some aftermarket rams horn exhaust manifolds, they will be made to except the "air" tubes and come with plugs if the system is not being used. Hope this helps answer your question. Tom __________________ Contact me on all of your gauge cluster needs. I specialize in restoration, repair and parts sales for 67-72 Chevy and GMC trucks. email me at tbonegarris@yahoo.com I am also a dealer for Counterpart for gauge cluster parts only. Also see my facebook page, CG&C



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