He believes it to be a 1971 but not registered until 1978 common with kit cars.
It runs a stock 350 on the Crown style Corvair transaxle. the front end is also Corvair but the frame is a custom 2×4 from Fiberfab.
This would be the last or “late” Valkyrie, it is a bit longer than the early ones and has the molded in front spoiler, you get at the engine by removing the rear louvers and in this example it also has a hatch between the tail lights. the doors are also longer on the late models and you can run one piece side windows.
What’s really rare is this one runs and drives great so it’s ready to play with.