I don't think you need much pressure form the fuel pump I had a fuel pump pack it in on the way home from the mountains towing car trailer loaded with a Torana late Friday afternoon and couldn't get parts purchased 10feet of fuel pipe filled 20 lt drum made a hole in the cap for the pipe .syphon fuel from the drum on the roof to carby and she never mist a beat only problem was i had to fill drum at ever town seeing I was keeping the level to approx 3/4 so it didn't spash fuel all over roof .
And this was in my original HZ in about 84