Good job. When the pan is off, have a close look at the cam bearings. If they look mushed out on the bottom side, that would be the oil pressure loss.
Just picked up a 67 Camaro myself. It is a RS convert with 250/ Glide. Rusty, needs plenty of sheetmetal.
Keep in mind, if doing the oversize valves, look real close at the valve guides to be sure they are not worn, otherwise, it will get a sloppy valve job and still want to consume oil thru the guides.
