I have a 89 GTA and bought it with 20,000 original miles. I would get startup smoke with it but thats it, never smokes under load or when Im getting on it. I thought maybe it was my valve guide seals but I have had to replace the number 8 plug twice since i bought it and have only put 3000 miles on it. I dont think a guide seal would wreck a plug that quick. Im thinking it might be a scraper ring. Im sure its sat a lot over the years and seals have gottin dried out. I want to put new heads and intake on it for a little more power and to solve the problem of smoking but if I have to pull the bottom end out I might as well stroke the engine out while im at it. Didnt want to do major work to it so soon but not to many other options. If anyone has any ideas I would like to hear them.

THANKS

 

sounds like valve guide seals to me. Those are the exact symptoms.The quick fix is to change them on the motor with the proper valve spring compressor. If you do decide to pull the heads, I'd send them to a machine shop and have a valve job done( guides, seals and valves ground)