Yes you'll have about 1/4" sticking out in the front splines (there is a picture in the install that shows that the replacement splines are bigger.
The splines are hard to get in if you don't have the bars lined up well. Best advice I can give is to take out the two small bolts on the front anchor so you can pivot it down about 70 degrees towards the ground. At this angle you should be able to slide the bar right in (no pounding).
So what areas were difficult? Anything that can be clearer in the instructions or was it just hard to do.