Well, if you indeed have an 88 YJ. Then you dont have a fuel sending unit. The 87- early 91 YJ's have the fuel pump on the motor. The only thing in the tank is the sending unit for the gauge and a pickup tube. And for us older YJ owners, that little item is like gold...lol. For some unknown reason the dealers and aftermarket companies want more for that set up than for a sending unit/pump combo that fits in the newer YJ's.
If you can weld or braze, it is a simple fix with a new piece of 3/8 gas line.