The purpose of the wide tire kit is to secure the signal wiring tight against the fender and to do away with the hex-head bolts which are used to mount the rear signals.
If your bike is not lowered, you should be able to use the wide tire without going to the expense of the kit. Just make sure your wiring is secured as tightly as possible against the inner surfaces of the fender. Also make sure your wheel/tire is centered in the fender and swingarm. If centered, the hex head bolts should not be an issue.
I've lowered my Super Glide by about 1.5". I had a terrible time with the signal wires when I had the 160 tire. There was no way I could have used the 180 without the kit with the signals in their stock location.
To resolve my issues, I relocated my signals.