Anyone done this? Doesn't seem like too uncommon of a conversion, just not sure which of the many filler/vent hoses to buy, and would like to buy the hoses first so i kind of know where to cut the hole for the filler neck.
I was speaking about the replacement filler neck, not the original.
The plastic tank should be for '77 and up as well. If it isn't, send it back and get one otherwise you're on your own transitioning the different sizes of hoses that each will take.
I would say '78+ since '77 was a unique year for gas tanks. They had the larger diameter hose like the 76 but with a nipple on the tank only about 2" long where as the 76 was about 6". I believe the 78+ never changed again only possibly difference being the 20 gallon tank vs the 15 gallon.
Indeed the '76 and '77 are the red headed step children of jeeps when it comes to the fuel tank. I have the same setup you do. The way I did it was to get the filler hose that matched the tank. Then I went down to NAPA with it and the filler neck and we found the 3-4 concentric size (fuel rated) hoses that barely slipped inside each other till I got down to the filler neck diameter and used a hose clamp to finish tightening things up. I only used a couple inches of each smaller hose, just enough to fit the filler neck. The filler neck vent tube is close enough to the same as the tank vent tube to use the same size hose.
With a great Jeep comes an empty wallet.