Solid motor mount install issue...

I was looking at my motor mount brackets when I changed them over to my new engine/trans and noticed that there's a lip in the rear bracket... Since i had the solid mounts right beside me, i tried to slide one into it and noticed that it won't fit because of this lip piece... I can easily grind it off while i have it all apart... I just wanted to check with someone who has solid mounts and see if i was doing something wrong or what because i searched through some threads and can't find anyone else who had to do this...

here's the bracket and i circled the lip thats causing an issue...