Hello, Bob. I'm using a Quicktime bellhousing with my Roush. For the motor mounts, I am assuming you are referring to the mount between engine and chassis, on the sides. There is a big block Chevy mount available at Autozone here that works perfectly. I can get you the number if you need it.
On bolting the bottom of the bellhousing to the engine, I'll have to take a look again to remind myself. I'm not sure what you mean by "rear hoop" or "collar". The bellhousing does NOT bolt to the chassis in any way.