With all the decades of talk about lifter bores leaking oil, I wonder why no one has ever sealed them. It seems you could o-ring them and that would last for at least a few races. I'll bet there are linear shaft seals out there that would be even better.
I also wonder why no one has said a word about improving the feed passages to the main off the galley. YR's method of feeding through the main caps addresses this by eliminating it, but if in fact the oil refuses to take a right turn at #4 (I don't believe that, but for the same of the argument) the crude 90 degree-drilled-hole-with-sharp-edges could be massaged or otherwise worked to encourage better feed.