With that much oil consumption I would think the additional lift has caused the valve seals and guides to wear. You probably had some gunk buildup on the valve stems which acted as an abrasive. One thing I have learned over the years is not to do a cam upgrade without reworking the heads, and it sounds like you have now learned that leasson, too.
Due to the miles, I would recommend a complete rebuild, top and bottom. If you rebuild the heads only with the higher performance components, the bottom end will wear out faster.
