Thanks for the info. Just spoke with Dave at ATI. This flexplate 915-660X works. It is sold with a kit which includes a crank adapter spacer 915-630X and bolts 951-471-6.
If running 8 bolt hemi pattern. The flexplate is 915-660X. The adapter spacer is 915-660X. Bolts 951-435-8.
I am still checking but reasonably sure this same arrangement will work with Reid sbm and BBm bells.
Thanks for the input guys. You led me to the answers needed. No sense in making a part if it already exists.