They were exactly 8 units apart as they came thru the wall from Fisher, roughly 10 minutes apart timewise. They then entered one of 5 active body bank lines on Chevy side (there were six banks but one was almost never used), so they could, based on their options be in any one of those banks, or in the same bank. The higher number VIN could actually end up in front of the lower VIN one if it was a basic low option car and the stars aligned properly, as they left the banks and continued thru Chevy's side of the plant.