New weird issue

you may want to pull the distributor and check the drive gear. they are plastic and start to come apart when they get old. maybe a few teeth broke off?

i think your close... just the wrong gear...

what kind of oil pressure were you having? did you change the oil pump out? sounds like a new oil pump gear failure... all the new gears are junk...

like above pull the dizzy, shine a flashlight in there and see what you see!