Blowin Smoke!, What Now? Options

[ericread]

On Friday, November 28, I drove from Irvine to Van Nuys and back (with a few side trips) to pick up a couple of cases of Brad Penn. A total of about 200 miles. No problems, and my car ran like a champ.

On Saturday, November 23, I replaced the front engine mounts, changed out the distributor cap, replaced the coil with a new Bosch Blue coil and changed the oil.

This morning I decided to take a trip from Irvine to Temecula over the Ortega highway (twisty mountain hiway) returning via I-15 and highway 91. About 150 miles. 40 miles into the trip I notice that I am blowing smoke upon taking my foot off the accellerator. Actually, once I hit the acelerator after coasting I get about a 2 to 3 second cloud of blue/grey smoke from the tail pipe. I continue my trip, but the smoke seems to occur any time I slow down/accellerate at hiway speeds, or even shift.

During my drive, my engine is running great! No missing, no vibrations, and the CHT never cracks 370 in fifth gear at 4000-RPM (~80MPH).

The first think I thought was valve guides, but why would this ocurr in such a sudden manner? And if it is, what next? The engine is really running great, and I'm getting about 25 combined mpg.

What are your thoughts, and what's my troubleshooting process?

My thanks in advance

Eric Read