Quick update: I replaced the gas filler hose last week. Everything works great, no leaks, but it was a bit of a pain. Below are a few tips, and I think I'll put a thread in the general maintenance with with same info.
Replacing the gas filler hose:
First clean out your trunk and remove all the trunk floor panels so you have access to the gas tank filler pipe.
1) I have a 78 gas tank systems, this procedure may vary a bit based on the year.
2) The thick, almost 90 deg hose connects a the metal gas filler tube (where the gas cap is) to a pipe inlet near the bottom of the gas tank that runs parallel to the ground.
3) First drain your gas tank as much as you can (but leave a little gas in (like 1 gal) so you can drive to the gas station when finished)
4) If you don't have a lift, jack up the car form the rear driverside wheel and then put a stand under for safety. You need to get under rear wheel area to work, and you'll have to muscle things around, so make CERTAIN your car is safely on stands, and you should also block a few wheels. SAFETY FIRST AND ALWAYS.
5) The hose is held in place by two hose clamps. One connecting to the bottom of the gas tank, one connecting to the filler pipe. I think there is an 8mm bolt that you need to turn to loosen the clamps, and then drop them either forward or backwards. The bottom hose clamp is easy to get to, but the top clamp is way up there, you don't have a lot of access and it will likely take some time. A very small ratchet, of better yet a small pivot ratchet is your best bet. I recommend wearing goggles because a bunch of junk will fall in your face while your on the ground looking up to the clamp. (And watch out for spiders in the area.)
6) Once the clamps are off just use brute force and work the hose off both ends and remove it.
Now that was by far the easy part. The hard part is getting the new hose on. After a few hours of trial and error, this is the method I got to work...
7) Now just connect the new hose and your done - right. In order to do this, I first removed the filler pipe. It is held in by two screw bolts near the gas cap. The bolts have a nut underneath that's hard to see. After you loosen them a bit, you have to find the nuts an hold them in place (by hand or pliers) in order to get them all the way removed (otherwise they just spin in place).
The filler pipe has an overflow tube and a another connection hose to the gas tank. You have to remove a clamp on the filler pipe and disconnect the additional small hose from the filler pipe. The overflow you can just move away by hand.
9) With the filler pipe "free", pull it up out of the trunk cavity. Put some lubricant (oil) on the filler pipe where the hose will need to slip on. Also lubricate both ends of your replacement hose, and the connection pipe to the gas tank.
9a) Either align the hose clams on the hose or put them our the filler pipe and the gas tank pipe. MAKE SURE they are in place before you go to step 10.
10) TRICK TRICK TRICK: The replacement hose is thick and basically makes a 90 deg turn. From below the car shove the hose into the cavity and shove it as far up as you can towards the now removed filler pipe. Make sure you have the correct part pointing upwards. As you shove it up the cavity, it will "bottom out" when it hits metal in the trunk area but you will be able to see it, and align it from the trunk area. Make sure the hose is generally aligned, that is the other end of the hose is generally aligned to connect to the gas tank.
11) TRICK TRICK TRICK: Don't conned the hose to the gas tank yet, GET A HELPER, and have them hold the hose in place from under the car. Then, from top going in through the trunk, slowly lower the filler pipe, and adjust the position of the hose, and shove/jiggle/cajole the filler pipe into the hose. The hose is thick and you have to muscle the filler tube onto it. But the hose doesn't have much room to escape, especially if the helper is cooperating.
12) Once it's on the filler pipe about half way connected, connect the other end of the house to the gas tank pipe. This part is pretty easy.
13) Push the filler pipe 100% into position and reconnect the bolts that hold it in place, position the over flow tube and reconnect the other fill tube.
14) Simply (Ha, HA, HAAA) put the hose clamps in place and tighten them up.
I had a very hard time getting the filler pipe clamp in position. As a result, I went through the trunk and drop in a second clamp and tightened it up just to be 100% sure it wouldn't leak gas. The top of the hose is below the level of gas when the tank is full (great design...not), so you really have to be sure both ends of the hose are well sealed/clamped.
That's it. Good luck and if you have original rubber down there, I strongly suggest you replace this before it fails. Just make sure you are very, very low on gas before you start.
Peace.
Out.