Long story short. I bought a used short block. I was unsure of the year so I told the local parts store it was a 1990 5.0 I get home and the oil pump is hitting the pan. The auto store told me that there is an earlier pan which is deeper? I also told them the car was a 1990 for the water pump and front cover. But all of that bolted up fine. Is there just a difference in years for the oil pan?