Stuff happens and you just have to move forward but have resolve that your never going to let this happen to you again. As far as the manifolds you must have missed that I commented in your other thread about them that first gens used a center outlet on the drivers side to avoid just what you are running into. You need to mock the other side also because even though most or all models used a rear outlet they can have different angles and clocked rotations for the flange.
