I have the Viking 18x8 Mega Quilter (same machine) but I only have the wooden frame.
I just looked at a demo of your frame on YouTube, and I don't really see any extra space in your take-up bar supports to allow you to install a deadbar.
You might be able to contact the Grace Company and see if they have an "upgrade" for your frame. With the growing popularity of the deadbar, they just may have what you need, for a reasonable price.