LA360 initial timing too high - are there different timing covers?

If your intake lifters leak down, the durations go down and the cranking compression will go UP. So it will only get worse when the lifters pump up. And I don't think your loss of exhaust duration shown on your timing wheel will not be enough to effect air movement in and out at low engine speeds and thus lower cranking compression.

Unfortunately, I don't think you can yet rule out serious cylinder or ring wear based on the data presented and the limited running use. With enough wear to drop cranking compression, you won't necessarily get a ton of blowby or oil smoke out of the breathers at low RPM's; BTDT. Who knows if the rings were seated right.....

Your cam choices are right where I would go. Keep the lifts in the.440" range or thereabouts to keep the stock springs and such. I would tend to stay with a shorter duration to keep the low RPM torque up higher for street cruising.