I have talked to Steve B. about his engine girdle that he uses on his Nitro motor, and actually saw one bolted onto a modified '59 block. It looks pretty darn effective! He didn't share any of the secrets that he put into it, nor would I repeat them if he did, but I got the impression there was more complexity in the machining and attachment to the block than meets the eye. I also think it was made of something harder than iron or mild steel.
Good luck with the one you guys are making, I know Steve will sell his kind to anyone who really bugged him for one, but he is not making them as a business as of when I visited his shop.