The gas tank in my dad's 89 TTA has a hairline crack at the filler neck. I just pulled the tank from my 91 Firebird and was wondering if the gas tanks are the same size/capacity? Thanks in advance.

It should be. the pump will be diff tho. Pull the sending unit out of the tank and look inside for the plastic baffles in the tank. If you have them you have the same tank as the 1LE and TTA cars. I cant remember exactly when they started using the good tanks in all the cars but it was sometime around 91..

Bring it by and I can run a bead of new solder around it.