Fuel Lines

I just bought a 1973 Plymouth Valiant. It has the 318 V8 with roughly 95,400 miles.The car sat for many years and the previous owner got it in running condition (rough). He replaced the gas tank and had someone cheaply rebuild the carburetor. The car ran fine but pressing the pedal too quickly caused a delay in acceleration. I got that issue fixed and the car starts and runs great. I understand/was told that the fuel lines in these older cars cannot handle newer gas and will eventually start fail. does anyone know or have an idea of which lines i can replace to prevent any issue before it starts to occur......well it may have already started as I can smell gas for days after filling the tank. Any help would be greatly appreciated.