Hughes heh237/242 in a 360?

The biggest issue is giving the engine the timing it wants a those low rpms.
It is IMPOSSIBLE to satisfy the engine at those low rpms, without a timing computer, and that is why everybody jumps on the "impossible" response.
Just try it for yourself; rev your SBM engine up to 2000, and start feeding it timing while simultaneously keeping the Rs to 2000. When the engine no longer picks up rpm, you have reached it's happy spot. Now put the light on it and tell me what you got; I bet it will be in the mid 50s.
Now; how are you gonna meet that need, and still have correct power-timing to fall back on? It cannot be done.
Your Power-timing at 2000 with a manual trans, to run 87E10, in an 11/1 Eddie-headed 367 will need to be limited to around 20 to 24. If you mod your Vcan to the max, you might find 22 to 24 Degrees, for a total of 42 to 48. You are still 6 to 16 degrees short. And so you light the fire too late and it chases the piston down, wasting energy. The lower your cylinder pressure, the worse it is.
On this trip, with the dial-back timing device, I had a 63degree max possible timing, at 2000 rpm.
So; just because my combo got 32 on that particular trip, doesn't mean yours can. And it doesn't mean mine can't do even better; I just slapped together what I had.

Here's the back-up math;
At 64mph,32mpg will require 2 gallons, which is ~12 pounds of fuel.
At WOT the rule of thumb is that your engine requires about .5 pound of fuel per horsepower per hour. Therefore 12/.5=24 hp; that sounds pretty close already.
But how lean can you run it at a steady 1600? IDK, I had no AFR on it.
Suppose I could run .375 pound of fuel per hp per hour.
That would be 12/.375=32hp, that sounds really close.