The Stovebolt Site Forums The Shop Area Engine Shop 66 / 283 exhaust manifold extra bolt holes....

working on fixing the exhaust -it started with the tail pipe falling off the muffler disintegrating, and all the donut studs breaking off. then these extra bolts in the manifold were so corroded a couple just fell out from the manifold.
inside these holes were light weight tubular thingies about 3/8 diameter and 4 inches long !
my stock rams horns seem to be shot because these 4 extra threaded holes are rusted out- no more threads.
my question is what are these things and what can i replace my manifolds with. i want to stay stock looking.
the alternator bolts into the front of the manifold. (i wont mention the corroded leaky freeze plugs i found during all this.... )
thanks for any info.
paul

That's the remains of air injection tubes- - - -one of the first attempts at emission controls. Those engines had a belt-driven air pump and steel tubes going to each of those holes, with a one-way check valve to prevent exhaust gas from getting to the air pump. The permanent fix is to remove those tubes, by whatever means possible, chase out the threads with a 1/4" pipe tap, and screw pipe plugs into the holes. If you want a really slick-looking repair, get some of the pipe plugs with an Allen-head socket in them instead of the square head a regular pipe plug has.
Jerry

thanks. this was a original california truck. i think the original owner musthave took that airpump stuff off.
these holes are past chaseing i think.
i am lookin for replacements. hard to find ones with the proper alternator holes.

Will the Dorman reproductions work for you?
674-504 Driver side alternator mount $60
674-503 Passenger side alternator mount $70
available thru Summit Racing.

regards,
Leon

Just drill & tap the holes for something larger, like a 5/8" bolt, for instance. Screw a bolt in snug, cut the head off with a hacksaw, and dress it up with a file. No sense buying a new manifold over that! The holes aren't important- - - -getting them plugged tight is!
Jerry