I don't have the same set up. I use a Juki machine. It has the same throat as yours and mine is on a Grace frame. I have quilted a queen size on my frame. The thing that helped me most on a large quilt is to make sure the quilt on the take up rail is rolling up tight. It makes the roll in the throat smaller. At the end of the quilt I had about 4.5 inches available to quilt. Also, it's best to use a low loft batting. I hope this helps a little.