If you're going through the exercise of bringing oil pressure to the cylinder base, IMHO, I would continue the design process by abandoning the skirt oiler in the K cylinder in favor of a piston squirter who's oil stream was directed to the underside of the piston crown (rather than across the bore at the piston skirt). See Frankenstein's site for pictures of his version of a piston crown oiler.http://dicky_linn.webs.com/flatheadpistonoiler.htmhttp://dicklinn.webs.com/
Having the oil stream impinge directly on the under side of the piston crown would be significantly more effective at cooling the engine than simply having the oil stream squirt across the bottom of the bore at the piston skirt. After all, the crown of the piston is where combustion heat is absorbed and the area you are desperately trying to cool, not the piston skirt. If you hit the crown with the oil stream, this would likely improve the skirt cooling anyway, since the oil stream hitting the crown will be splashing or draining over the skirt as it returns to the bottom end.
If you undertake such a project I'd stick with a ~ 0.040" dia orifice in the terminal end of the squirter (same size as in the stock K barrel), since this will flow lots of oil if pressurized properly.