The 440 in my Belvedere is supposed to have been rebuilt low mileage etc etc.

When I got it it was running dual breathers into the air cleaner. I went back to a singal breather and PCV valve.

I've noticed it's always had visable smoke from the breather but latly I am getting some oil from the distributor vent holes dripping down after long runs and the breather has actually dribbled a little oil out thats run down the valve cover and hit the headder.

I need to down a cylinder leakage test but safe to assume this is "too much"? Car still runs great makes decent power just getting hard to ignore the smoke.

Stuck or bad rings...

Doesn't sound good assuming the motor has a pcv on it, even if it doesn't still doesn't sound good. only other reason for oil out of the breathers would be non baffled valve covers. But the oil from the distributor???? Sounds like excessive crankcase pressure, IE: Leaking compression rings

Rings never seated properly or glazed cylinder walls. Have you tried running it up tp about 50 in low gear and letting off several times? you may want to find out who built the motor and see what rings they used. Possibly low tension rings?

What do the spark plugs look like? This might sound stupid, but how much oil is in it (over-filled)? (If the oil level in my SBC plow-truck is at all above the "max" mark, it pumps out of the valve cover grommets.)

You don't say when it was rebuilt. My guess is that the engine got too hot at some point and the rings are trashed. Blow by as you see it is a sign that the compression rings are not working. You are not clear whether it also is fouling the plugs, if so, that would be a sign of the oil rings being stuck too.

If the build was a home job, it's possible the guy did a poor/coarse hone job and then installed Moly rings. The coarse hone would destroy the moly in short order and leave this problem too.

Astrobuf

Supposedly had 7000miles when I bought it. Was done as I am told in a shop.

Oil level has been check by pan number and filled to 4 liter in the pan with a full oil filter no change in the amount of blow by so it's definatly not over-filled.

Plugs are a bit rich looking but never oily and no blue smoke or oil stink from the exhaust.

If It's a broken ring or a poorly fit one what are my chances of getting away with just a hone job?

You will need to tear it down to assertain the internal damage to make a decision on whats needed to repair it...

mine sounds just like yours except for the dist oil, only mine is an original standard 383hp, I'm just living with it now no real smoke or smell just the blow by. For the 800 to 1,000 miles i put on it a year not to worried.