Look around for Grant part #s and order from the local guys.
"Topline" may also have them. If you can find a Topline parts #, hit me with an email with your sizes. Topline is one of my sponsors, 1 mile from my shop.
The Grant are soft and seat easy.
The "total seal" make power unitl the parts fall out.
If you are building a race engine, why would you scrimp on the rings?
IMHO,
MM