I just removed the flex fan off my 72--454 with long pump and replaced with a 772 fan with a HD clutch. When I got it back together the new fan hit the top of the shroud. It clears the opening fine but the top of shroud slopes back to the radiator and that is what hit. If it was straight across at the top (depth) it would work fine. Before I order another is there a difference in the top with the SB and BB that would do this. I am unsure what shroud I have.