When my car ( 1991 305 TPI) has been parked for a couple of days and I start it, a big puff of white thick smoke comes out of the tailpipes. It lasts a couple of seconds and the disappears.
I am thinking bad valve seals letting oil leak into combustion chamber. Am I correct or could it be something else?
Rick

 

Thats what it sounds like. Mine only has to sit for a few hours, and it gives a puff of greyish smoke. I have heard this is common on TPI engines.

 

valve seals will liek oil which will burn blue
coolant burns white could be head gasket or cracked head

 

Common problem with SBC engines. Valve Seals in most cases.
I would also check your coolant tank over a period of time for any fuild loss which could be another problem.

 

Yea, during the day mine does look blueish, I thought that was because the blue sky. At night it looks greyish. What ever.

 

Valve seals for sure. When you go to replace them get positive type seals for both the intake and exhaust, instead of half positive and half umbrella (which is what the store will try to give you.)