I'm new here, just found this site today and impressed with the knowledge around here so i figure i'll see if anyone can help me. I have a 406 sbc i built a few years ago thats giving me all sorts of issues now. It has dart iron eagle heads that have been ported and machined down, mechanical cam and lifters, holley double pumper 750cfm and a edelbrock air gap intake. Ther first problem is it has been blowing oil out of the breathers, it has done this since i built it, its never had a pcv valve on it, just 2 breathers and i've read a bunch on this site but i'm not sure what to do to reduce the crank case pressure and if this high pressure is bad for anything, the motor never see's over 6k. The second problem which is the real pain is that once the car warms up it dies if i get anywhere near idle. If i let it cool down it will start on the first crank but to get it to start say when im sitting at the stop sign with 10 cars behind me i have to pin the gas like its flooded till it starts to stumble then pump the hell out of the gas and get it moving before it dies again. I'm leaning towards the carb on this one but i figure before i pull things apart i get someone else's opinion.
Any help would be greatly greatly appreciated
Thanks,
-Ryan  

Idle issue sounds like carb...re-adjust floats and set idle mixture screws, base should be 2 1/4 turns out would be good start....make sure needle and seat are clean also.
as for crank case pressure....well you know the answer to that...BLOW BY!
Hope this helps...also check timing.  

Very possible that the engine has been way too rich it's entire life - the rings may not have never seated, or if they did they could be worn by a continuous dry condition.  

sounds like your cylinders are have been washed with fuel caused by the rich condition,in turn causing the rings not to seat properly from day one.  

Is there an echo in here?  

the only echo i hear is coming from between your ears.........  

Thanks guys for the quick response, This problem hasnt been with the motor its entire life so i'm hoping the rings did seat. Can i be sure of this by doing a compression check? This motor used to run like a top, very strong, theres never been any smoke out of the pipes nothing like that so i'm hoping this isnt going to be anything real huge.  

You said in the first post that there has been smoke coming out of the breathers ever since you built it - now you're changing your mind?

A compression check couldn't hurt.  

No, The car shutting down when warm and coming to a stop sign(near idle) has not happened it's whole life. I just reset the idle screw's, the carb manual said 1 1/2 turns out. Its hard to tell if this really helped untill i take it out and drive it. Before i do this though i thought it would be a good idea to check compression. Also if this doesnt work i have a brand new holley 700cfm that is about to go on another project car that i was thinking of throwing on there to confirm/rule out the carb. Thanks to everyone who has helped so far.
-Ryan  

Ok, i have checked float levels and idle mixture screws, i also swapped carbs with a brand new holley 700 we had. No change. Pulled all the plugs it looks like its running a little rich. I went to check the timing and found the light is broken....this has a MSD 6al box with a coil that is mounted near the header, on the inner fender,it is wrapped to help with the heat but i was wondering if this could be the problem?
Thanks
-Ryan