The stroker in my Mustang has 1300 miles on it now. Its a 347 with probe pistons, but does not have the soft rings you have in the Chev. In the first 30 minutes of running in an engine trolley it blew clouds of oil smoke, then stopped once the rings seated. In the first 500 road miles it used about a pint.
Since the first oil change it has not used any noticeable amount up to 1300 miles so it would appear you have some serious issues there as mentioned above by other postees. Maybe a leak down test will give you a clue.
By the way as i have close tolerances on the crank i run 10/30 hipo Fuchs Oil.