Smoke Diagnosis - 427 s/o

[Archrms]

At initial start up there are no problems. The issue starts when the engine is turned off after driving, like after filling up at the gas station, and then started again. When it starts back up, there is an initial cloud of smoke, then again only after revving the engine. The smoke appears after the revs drop back to idle, not during the rev. The smoke is light colored, not dark nor pure white.

I had a small oil leak at the sending unit which I just fixed, so I can't yet tell if I am losing oil elsewhere. Coolant always seems to be slightly below the neck of the puke tank.

The engine has a solid lifter cam with dual carbs, and 1,100 miles on it. The plugs need to be replaced and valve lash is due for adjustment. Any thoughts on what may be causing this, or where I should look? Does it sound like a potentially serious problem? The car runs great other than the slight smoke issue. Any insight would be appreciated.