When I built one 6 or 7 years ago I modified the kit hinges to fit the hood per the instructions.
Keep in mind that the 379-127 sits much lower off the frame than the 378 does. The cab mounts and sleeper mounts need to be mounted lower so that the cab sits lower.
I test mounted the cab first, then the hood, adjusting the hinges so that the hood and cab lined up and kept the hood plumb.
Since the cab is lower, the air cleaner intake pipe will need to be shortened slightly and the exhaust under frame piping will have to be lowered. Don't glue the crossover Y-pipe frame mounts to the frame, glue them to the pipe. Then install the pipe and mounts after the cab is installed so that they line up with the mufflers and elbows.
Tim