smoke

I have an 88 gt with 128,000 miles on it, runs like crazy, but i have noticed now that its warmer out if i ride a gear lets say 2nd from like 4k down i will see alittle bit of smoke after i come to a stop. its not alot of smoke, kinda whitish in color. it doesnt smoke on start up warm or cold, just when i do this.. any ideas???

thanks