Hows it going family , i got a short question . Ok olds 1973 455 into 1979 cutlass , gas tank has two lines coming out , one down passenger side ( to fuel pump ? ) and the other down driver side ( return line to tank ? ) fuel pump 3 lines outer is fuel in , small middle one is fuel return and inner threaded line is to carb. ?

 

You can get a different pump with only two fittings - inlet and out to the carb. Just look around other Olds applications. Some cars were set up with a return line to address vapor lock.

The smaller line on your tank should go to a vapor/charcoal canister. Maybe? I'm not familiar with the emission controls on the '79.

 

Your 1979 Cutlass did not use fuel return. The pipe on the passenger side is the feed line from the tank to the pump. The pipe on the driver's side is the vent line to the charcoal canister. You can either replace the pump with one that doesn't have the fuel return line or you can cap that port on the pump you have. It won't matter either way.

 

so capping the middle one want flood the carb or blow the line ?

 

I wouldn't have told you to do it if there were side effects.

 

Thanks .