on my 79.supply to fuel pump is cracked and i want to change it.anyway to do this without emptying gas tank.also is hose attached to internal pump in tank.do i have one on my 79?hard tofind fuel hose routing.ive looked in service manual,but not a lot of info.most is for 1980 and up

 

I have a 1978 car MY 1979. The hose from tank to pump is readily available from Porsche. Outlet tank is larger than inlet pump so make sure you have the original part. I do not have a pump in the gas tank. Only a level sensor.
Also buy the seal between screen and fuel tank. And yes, do empty the gas tank before changing the hose and seal.
Btw, the pressure line to the fuel accumulator and the vent hoses are also old and brittle sk best thing is to change them too. I think Roger selks a set to make the pressure hose.