i recently bought a 87 trans am firebird 305 5-speed with 98k original miles and i noticed when i start the car it puffs out some white smoke that smells like oil. could this be the valve seals or piston rings? or something else?

 

Yes, most likely the stem seals are dried up/brittle and broke up.

 

im going to replace them myself but is the tpi going to be in the way?

 

No, the valve covers will come off with some finagling, you probably will have to take of the AIR diverter valve, there's a 10mm headed bolt to the left (firewall side) of the plastic box, then unsnap the plastic box and you'll find another 10mm headed bolt.

Then you can sorta pull it back out of the way.

Driverside is pretty painless.