[Shotimes] Oil, smokin', blowby?

[Mark Mucher]

My '90 (no EGR) just started leaking oil, smoking, etc.
 
It always had a drip from the front main seal which dropped on a cat an
smelled a bit.  (It got better using high mileage 10W-30 Castrol).  I tried
the Auto-RX leak stop routine but it didn't help.  Then I went back to the
Castrol HM.
 
Now I get an oil smell when I drive and it smokes (comes out in front of the
battery) when I stop.
 
Looked under this morning and and there seems to be a lot of drips going
back the passenger side, but I can't see where it's coming from.
 
There is (and has been) some oil residue all across the top of the front cam
cover, but not enough to drip down on the manifold to smoke from there.
 
Seems like it's caused by pressure in the crankcase - what could be blocking
that?
 
All suggestions appreciated - (It's still in the air!)
 
Thanks in advance,
 
mm in sunny FL