Can clogged ports in a car engine cause smoke at ignition?

I have a 1995 Ford Probe SE 2.0l 4cyl and it used to only smoke at start up after sitting over night when it's cold outside, but now the weather is warm and it is starting to smoke after sitting only a few hours. I put Lucas oil stabilizer in for the first time about 2 weeks ago with the oil change and thats when the smoking became worse. I am begining to wonder if the Lucas has clogged something up that would let oil settle back into the oil pan. I thought the problem was just valve stem seals, so I used the Lucas to try to help stop the leak until I can pull the head and get it redone, but now the smoking is occuring more often. The oil I've used the whole time I've had the car is 10w-30 Motorcraft synthetic with a Bosch oil filter, but this most recent oil change I did I used the same oil, but substituted some oil with Lucas and changed to an STP filter. Is my problem really valve stem seals? Is it getting worse because of clogged ports in the engine cuased by to thick of oil? Also I know the rings are good because compression is good and it holds compression. The car has about 152,000 miles and I'm the second owner and have had the car for about 8 months now. Someone please help me, this car has to last me until I graduate school and get back from basic training for the Army or Air Force. The car has to last until then because my parents don't spoil me and buy me everything, I had to buy the car my self and I have plans of getting something nice, used, and sporty with my money after basic. Someone please help.