Ted posted a while back that the studs for the intake manifold at the center on each side on early heads thread into a hole that is open to coolant and can seep.  Sealer on the threads fixes it. 

John - "The Hoosier Hurricane"

Check the Heat Riser in the exhaust system, if your car has one? It may be stuck closed..

Paul

Would nearly bet its the paint burning off on the center exhaust cross over part of intake manifold, this can be reduced by blocking off the gasket in that area with small thin piece of brass shim or metal. There are truck intake gaskets with smaller hole in this area. This has been mentioned regularly on the site. best regards bill.

  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia

On two occasions after driving my newly-rebuilt 272, I noticed a small amount of smoke in the area of the left valve cover (as you're looking at it) near the intake manifold. Almost as if something was burning off. The oil and coolant levels were fine. Am I worrying needlessly?   

"You can lead a horse to water...but a pencil must be lead."

 

Cleveland, Ohio