Breathing new life into the 318 in the Scamp!
I agree. Modding the pan is where I am at with this. I'm just gonna roll an edge with the plenishing hammer head that I made for my air hammer and set it up on a block of wood. It will move enough to clear. I think most of my problem is just in the curvature of the pan's corner.
I'll check pressure when I put it back together. You may be on to something with a mislabeled part.
If the 340 has a taller pump, I'll just skip on that.