10.5" flywheel for a slant 6?

I dug this out for a member but I think it's for a slant 6. (evenly spaced crank bolt holes) The number isn't in the Galen Book. (not high performance enough I guess) It may have came from a pick up with O/D from what I saw on another FABO thread. What bellhousing would you need to use it in a car? Just curious and spit-balling here.

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