Smoke coming out of PVC on valve cover?

Definitely sounds like cylinder head valves inproperly adjusted and/or rings on the pistons worn. Do a compression check!!! Take the guess work out of it.

Hello,,did you shake the pcv valve? when you take it out it should be able to "rattle" when you shake it, maybe you know this, but otherwise it could be your valve guides are allowing some blowby . 60 over is just another way of saying you added more pressure on the valve guides, if you forgot to include them on your rebuild, well,, chalk it up to experience. The oil viscosity is a real factor as mentioned before. Don't expect to used generic oil and have great results. If you've been "beating" on the motor, say you did not give it the break-in time after rebuild, well it is going to need worked on again. No other way to fix that blow by. Also the carb(whatever) cannot handle all the smoke being recirculated back into the fueling ,that causes the sputtering, one thing leads to another, no offense,,but original works better. Been there done that,,1969 396 ,1971 350, 1968 289,,always something "cool" to be messed with,,bore them out, add headers, bigger carb,cam,rearend gears, jack'em up add Mickey Thompsons,,brings back some old nightmares too..good luck,,change the oil..

Could be excessive blowby from the combustion cylinder. Did you put in oversize pistons and rings when the engine was bored out?

Some pressure in the crankcase is normal. Part of the PCV valves job is to let that pressure out and vent it to the air cleaner. What looks like smoke may actually be oil vapour/mist and that is normal.

As for the engine missing when you accelerate; well, it may not be related to the 'smoke' at all. That sounds like a timing or fuel delivery issue.

Definitely you have a "blow by" problem. This is caused by escaping pressure out the piston bores. This pressure can escape through the valve seals or crankcase ventilation (PVC means Positive Crankcase Ventilation). Since you mention your car is .60" over bored, maybe the piston rings haven't seated or "broken in" properly. Or the ring gaps were installed improperly (staggered with less than 120 degrees of separation). Oil in the combustion chamber will cause "misses" and produce a grayish/blue smoke out the tailpipe. Excessive pressure will come out somehow, somewhere, and can cause serious problems to the engine if left unattended.

well i had a similar problem 305 268cam, oil cameout the breather then pcv valve think the motor gonna go .mineblew pistons out the oilpan

Too much oil or wrong viscocity. or a messed up oil pump or the return line clogged. Easiest things first check the oil level. Change the oil too if too dirty

change the PCV valve ...ventilation is there for a reason...what's your air cleaner look like?

Sounds like blow by