A good welder could weld up the upper part of the crossover, or use a block off plate. The Edmunds(that I'm aware of) is made for the small port 331s. See how they match up. There are a number of problems trying to use 392 heads on a 354 block.
One piece intakes will not fit if you have tall deck (392) heads on a short deck (331-354) block. The Edmunds were made for both the small port (51-53) and big port (54) heads. Which do you have? IIRC, all Edmunds have a t-stat so you need to check port size to determine which head matches the intake. You could run the small port intake on large port heads, been done many times, just not the most efficient. You can still use the truck heads, there are two relatively easy solutions, but you will still have water in the manifold: ...Weld a tab onto the intake to cover the port. ...Once the heads have been cleaned, fill the top portion of the port (in the head) with Devcon or something similar. This discussion needs to be moved to a project thread. .
331/354 and 392 heads have a key difference (well, more than one). There is a bit of the intake/water/heat riser runners that protrudes out of the main body of the head, toward the intake manifold. This section is longer on a 392. Chrysler did this so that, despite the increased deck height on the 392, it could use the same intake as the 331/354. You can put 331/354 heads on a 392, with some spacers (mimicking the 392 head's longer runners), and use a standard one-piece manifold. If you put 392 heads on a 331/354, the manifold mounting surfaces will be too close together for a one-piece manifold. I do remember one aftermarket intake, long ago, that would fit this application, but I have lost the memory of the make/model.
Figured I would add this to this thread. https://www.enginelabs.com/engine-tech/whats-old-is-new-again-early-hemi-engines-deliver-big-power/
The Jalopy Journal
