Sound like a tuning Problem? Or Exhaust?
 

My 88 TII drives fine, if I don't get on it at all, but when I get on it and really boost or raise the revves and then let off quickly, I smell gas and see white/gray smoke behind the car. Then the smoke is gone again. I have a RP downpipe and midpipe, meeting the stock (small) y-pipe and some half decent Bosal Mufflers. The car is streetported and doesn't have many miles on the motor at all. I haven't driven it much, and it really does need to be tuned (stand alone Microtech), because it hasn't really been run or tuned at all since the cats were removed.

I have been told that the car will blow out smoke when it is running rich and the exhaust is restrictive after the dp/mp because the gas can't ignite as it exits the exhaust system. But, since its not black, I would like to get another opinion.

Well, I would have to say it is gas also because when you are running under high boost it is probably rich for safety and then when you let off there is extra gas in there that has to go somewhere. It should go away when it gets tuned under boost.