'73 Buick 350 intake manifold freeze plug DIY advice

Discussion in 'Small Block Tech' started by daveyt, Jan 28, 2021.

  1. daveyt

    daveyt Member

    Hi everyone; I just got the exhaust manifold gaskets put on on my Skylark and it turns out that didn't temper the loud tapping noise coming from the back of the motor...turns out one issue is that the freeze plug at the right rear of the manifold needs replacement.

    Seems like a nice DIY project. Anyone care to share their knowledge on how I can do this right?


    That photo is not my intake manifold but it's the same concept. The plugs are on the "4 corners" of each end of those pool-stick-looking chambers.

    Appreciate it.

  2. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Those are the A.I.R. tubes. They hook up to the air pump. It's for emissions, air is pumped into the exhaust ports to promote more complete combustion after the fact. Not really familiar with the plugs, but if they are like freeze plugs, probably not hard to replace. Is the air pump still there and operational? You could just eliminate all that with a different intake and plugging the passages in the heads.
  3. daveyt

    daveyt Member

    Reminds me of my California-smogged 76 pontiac grand prix 400 sb that was rated at 185 hp haha.

    Great idea to swap out the intake manifold some point soon.

    Here's my IM:

    Attached Files:

Share This Page