67 Plymouth Fury Motor Questions

I have two questions:

1.  I changed the oil in my Fury.  When the car is idling the oil light flickers but as soon as you give it gas it goes away.  So everytime I come to a stop the light just flicks on and off.  What could cause this?  

2.  I was on the highway tonight doing about 65mph.  I kicked it down and a big billow of smoke came out the pipes.  What could cause this?  Bad seals?  

Thanks Guys.  

Actually it was black smoke that came out.  I found this on the Internet.  I bet my carburetor is out of adjustment.  What do you guys think?  

Quote:
"Black Smoke: Black smoke is caused by excess fuel that has entered the cylinder area and cannot be burned completely. Another term for excess fuel is "running rich." Poor fuel mileage is also a common complaint when black smoke comes out of the tailpipe. Black smoke out the tailpipe is the least cause for alarm. Excess fuel will usually effect engine performance, reduce fuel economy, and produce a fuel odor.

How did the fuel get into the cylinder in the first place? Some of the causes of excess fuel are a carburetor that is out of adjustment, a faulty fuel pump, a leaky fuel injector, or a faulty engine computer or computer sensor. If black smoke is present, check the engine oil as in the white smoke example to make sure excess fuel has not contaminated it. Do not start the engine if a heavy, raw fuel smell can be detected in the engine oil. Call your mechanic and advise him of what you have found."  

Your oil pump could be going bad or your main bearings are.  I have a 68 Fury III with a 318 ci.  Recently I had the same problem I bought a Milodon oil pump last year figuring the name brand would be good.  I fixed my problem by putting a MOPAR pump on my car.  I plasti-gaged my bearings and they should be replaced now, but the new pump puts out 80 psi cold and averages 60 psi hot with 10w-40 oil.  To check this put a mechanicall gage on your motor.  I believe that your engine should have at least 10 psi at idle (more would be nicer though).