Smokey Engine

Well I have a 1976 nova with a L6 engine. I haven't really been using this car much in the past years, but am begining to use it more. I know that the engine has always smoked, but now once in a while (especially while sitting in traffic) the engine stalls and won't start up for a few minutes. It doesn't overheat or anything, but I think the smoke might build up under the hood and choke the engine.
A while ago my mechanic said it was a leaky manifold, but the smoke doesn't really look like it's coming from there. It comes from the back of the engine block right before it connects to the tranny, but a little higher. The smoke doesn't start at all until the engine has warmed for at least 5min. It continues to smoke after the engine has been turned off for about 5min. It also seems to smoke more at lower engine speeds. Otherwise the engine seems to run fairly well. What do you guys think?

This is really I wild guess and if anyone else reads this thread, just go ahead and say im an idiot. But i think it could have something to do with your oil pump. Or you have oil leaking on to your exhaust causing it to burn off in a smoke. Then Yet your engine stalls do to the smoke getting into the carb. (No Oxygen). So other than that I could be wrong. But check for oil leaks around where the smoke is coming from.

-Hope that gives you and Idea.
-Take Care

Replace your distributor gasket. It could be bad and causing a vaccum leak and leaking oil. The leaking oil causes the smoke and the engine dying is from vaccum being lost.

fyter 87 is right i think b/c the same thing was happen to my 73 nova and i changed the val covers and it dont do it no more but horsepower might be right.