Thanks, that's really interesting about the idle speed. Since I installed this engine it's been idling at 1100, except this spring I installed Speeduino mapped ignition and dropped the idle to 950, just because I could really. I did maybe 2k miles like that before I found the damage.
It would be very nice to not strip and rebuild the bottom end this winter to drill that oil jet.
Maybe I'll just fit the new springs, skim the head up to 12:1 and finish the conversion to EFI.