Just noticed my 79 is leaking fuel on the passenger side near rear tire. What is the difficulty factor on replacing the line on my own? Do I need to drop the tank?

The '79 is different, but the fuel lines will still go to the pass side of the frame in the rear. Jack it up(and use jack stands for safety!), and see if you can determine exactly [b\where the leak is originating. It may be a fuel line, but it may also be a hole in the tank.
The rubber lines are not that hard to change....just hard to get to. You should not have to remove the tank, but it really depends on where the leak is...

Hey, before you do too much. check the rubber lines where they come out of the sending unit. Mine had a new clamp that broke and was causing a steady drip of gas behind the passenger rear tire. Just a thought.

Just went looking to purchase the fuel lines and found this note on the "ZIP" website

Note: 1963-1982 gas tank to fuel pump fuel lines cannot be installed without removing the Corvette body from the frame.

yeah....great idea, eh?
The lines, as they are run, go into the rear frame area at the kick-up. You can snake a short section in, if you want to splice a piece in, and use compression fittings. Otherwise, you'll need to pull the body up off the frame. Same deal with the brake lines, but using a compression fitting on brake lines is a no-no.
 A fuel line can get by with a compression fitting/splice, since the pressure is not very high. Actually, anything before the fuel pump has no pressure to speak of, except in the '82s.
You should, however, check the entire length of the fuel line. If it is corroded enough in one spot to be leaking, chances are it has other problem spots.

I have not ever replaced the steel  fuel lines but by all accounts you have to raise the body the reason is because the back 1/3 of the fuel line tucks  under the body from the rear x-member rearward, with the prebent replacement line because of all the bends its suppost to be impossible to fish it under the body because some other bend is hangin up some where, but all is not lost, I'also read that instead of useing prebent line you buy a coil of the correct dia. fuel line and use it instead and it is available, the way you do it is get the car up on jacks with plenty of room to work, uncoil the line and starting at the front of the car  fish the line rearward straightning the tubing as you go, when you get to the back it should be able to slide in between the frame and body, when you get to the back and it can't go back any more work your way back forward and make your bends as you go, make sure you have extra up front  to allow for bends, cut off the extra when your done....if working by yourself its easier to uncoil the line out in front of the car about 20' of it and fish it over the suspendsion and pulling it rearward, like I said you can cut off the extra later after your bends are done, good luck.  anips2010-05-16 17:58:36

Silly question..... Can the body be raised without taking it completely off, I am pretty good with the  nuts and bolts stuff but raising the body is another issue