I have a small port intake on big port heads. I ended up gluing 239 intake gaskets to 292 intake gaskets. Try a dry fit to see if you have room for 2 gaskets. I'm guessing you want to keep the 2 barrel set up?

  Dennis in Lititz PA

Adapters are readily available.Not the best way to go though.

  

The 239 intake will bolt up to the 292 but the intake and exhaust ports are larger on the 292 so the manifolds are a mismatch with misaligned ports. Therefore I would not recommend it. If you want to go to a 4bbl carb. on the 239, you can use a '54 Mercury 256 intake but this will limit you to an old style "teapot" carb. unless you find an adapter. Alan S. Freeman

I have been told thet most parts are interchangable on differant year Y blocks, except 54 239's that was a year by itself.
my question is would a Intake manifold from a 239 fit on a later 292?