I would hate to drag my boat all the way to New Orleans next fall just to find out it is not OD compliant. So...
I've measured the positon of the mast step and it appears to be about 1/8" - 1/4" too far forward when measured from the outer edge of the step. When measured to the inner ledge that sits inside the mast I am within spec. In other words I am off by about the wall thickness of the mast.
My issue is that before I tucked the boat in for it's long winter nap, I tried to move the step back. I tried to loosen the screws (phillip head). I even tried using an impact driver to no avail. I am afraid of snaping off the screw heads.
I have tried beating on the mast step with a 5 lb sledge (a block of wood was in between hammer and step)
As a last resort, I saturated the screws and mast step with WD-40 and left that to sit over the winter.

I'm worried that over time that perhaps the stainless steel screws have been corroded/welded into an aluminum plate that is below the mast step. If I break the screw heads off, is there a way to tap for new screws? Other than the danger of igniting the WD-40 and setting the boat ablaze, would heating up the screws help?
Any thoughts?