Taking off the 230's manifold revealed a couple of issues. First issue was that the number 2 and 5 cylinder exhaust surfaces on the manifold were heavily pock-marked, indicating that those two areas had been leaking for quite awhile. Since the engine has only 40k miles, I'm guessing the Flint factory's sealing job was marginal from the very start and that it probably began leaking shortly after the car was purchased.
The second issue was that the manifold's number two exhaust port had a small but clearly visible crack that was allowing smoke to exit (I tried to get a picture of the crack, but my digital camera's resolution and flash weren't up to the task).
Hmmm...what to do. One of the best things about driving 1,600 miles round-trip to Austin, MN to buy the 40k mile 230 engine from a little-old-lady '70 Nova was that I had essentially an identical twin to my '69 Camaro's original 250. Aside from the obvious cubic-inch difference, the only real differences between the two engines are that the '69 head employed an AIR pump (its head has ports for the air pump's tubes that the '70's head lacks), and the '70 used a carburetor stove for the air cleaner's Therm Vac setup. I pulled the '69's manifold and it was smooth and clean...no issues. To make David K happy (
) I separated the manifold (for the uninitiated, the "6-banger's" manifold has an intake half and an exhaust half that are joined by a square gasket) and replaced the gasket that joins the halves.
Ok...now the beautifully-running 230 from the little-old-lady '70 Nova has the manifold from the sick, vibrating 250 from the 46k mile '69 Camaro (just wanted to fully explain this little hybrid arrangement for anyone who came into the story late).
How does she run?...PERFECTLY!!!
