Need help!!! 1965 power steering nightmare

There is NOTHING wrong with using a Saginaw pump. Just because it might not have originally come on your car in '65 doesn't mean it's wrong. If it fits, if it works, and is a good pump, use it. Your car and your steering box won't know the difference. Mopars have used MANY different makes of pump, from slant sixes to big blocks, over the years.