Wish you had more, better pics. I'm thinking it's some kind of import, but not sure. Looks to be 70's or 80's vintage, the dist cap looks as though it might be some kind of electronic ignition, but it still uses carbs, so that limits the time frame somewhat. Another reason I think it might be imported is how narrow it is, something like 60* or less banking, and the fact that the intake and exhaust are on the same side of the heads instead of being a cross flow., and the use of dual carbs. The aluminum valve covers are another giveaway, domestic engines almost always used stamped steel valve covers, while a lot of imports use aluminum.
What ever it is, it would look cool in a open hooded roadster!