Yep, heavy 203 no doubt.
Most absolute way to check if its been converted is to remove the large aluminum half of the rear output assembly and check the differential inside of it for the part-time gears. The differential will look like a round planetary setup with 4 gears inside of it that spin around the output shaft which goes in thru them. The part time gears will have teeth on half of them and the opposite half will have no teeth.
Kind of hard to explain what the part time gears look like without a picture.